Maleic acid half ester terminated polystyrene macromolecular monomers having a substantially uniform molecular weight distribution

ABSTRACT

WHEREIN R IS LOWER ALKYL AND R&#39;&#39; IS EITHER HYDROGEN OR METHYL AND N IS A POSITIVE INTEGER HAVING A VALUE OF AT LEAST ABOUT 20, AND ALKALI METAL SALTS THEREOF.   -(CH2-C(-R&#39;&#39;)(-C6H5))N-CH2-CH2-OOC-CH=CH-COOH   1. A COPOLYMERIZABLE MARCROMOLECULAR MONOMER HAVING A SUBSTANTIALLY UNIFROM MOLECULAR DISTRIBUION SUCH THAT ITA S RATIO $W/$N IS NOT SUBSTANTIALLY ABOVE ABOUT 1.1, WHEREIN $W IS THE WEIGHT AVERAGE MOLECULAR WIEHGT OF THE MACROMOLECULAR MONOMER, AND $N IS THE NUMBER AVERAGE MOLECULAR WEIGHT OF THE MACROMOLECULAR MONOMER, SAID MACROMOLECULAR MONOMER BEING REPRESENTED BY THE STRUCTURAL FORMULA:

United States Patent O 3,842,050 MALEIC ACID HALF ESTER TERMINATED POLY-STYRENE MACROMOLECULAR MONOMERS HAVING A SUBSTANTIALLY UNIFORM MOLEC-ULAR WEIGHT DISTRIBUTION Ralph Milkovich, Naperville, and Mutong T.Chiang, Palos Heights, 111., assignors to CPC International Inc.

No Drawing. Application Aug. 21, 1972, Ser. No. 282,099,

now Patent No. 3,786,116, which is a continuation-inpart of applicationSer. No. 244,205, Apr. 14, 1972, which in turn is a continuation-in-partof application Ser. No. 117,733, Feb. 22, 1971, now abandoned. Dividedand this application July 2, 1973, Ser. No.

Int. Cl. C081 7/04, 27/12, 27/00 US. Cl. 260-78.4 D 18 Claims ABSTRACTOF THE DISCLOSURE This application discloses a copolymerizablemacromolecular monomer having a substantially uniform molecular weightdistribution such that its ratio of Hw/Hn is not substantially aboveabout 1.1., wherein IIw is the Weight average molecular weight of themacromolecular monomer, and Mn is the number average molecular weight ofthe macromolecular monomer, said macromolecular monomer beingrepresented by the structural formula:

i ii R-CHs-C CH2CH2 C wherein R is lower alkyl and R is either hydrogenor methyl, and n is a positive integer having a value of at least about20, and alkali metal salts thereof. Also disclosed is a method forpreparing the novel copolymerizable macromolecular monomers.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisionof co-pending application Ser. No. 282,099, filed Aug. 21, 1972, now US.Pat. No. 3,786,116, granted Jan. 15, 1974. Application Ser. No. 282,099is a continuation-in-part of co-pending application Ser. No. 244,205,filed Apr. 14, 1972, which in turn is a continuation-in-part ofapplication Ser. No. 117,733, filed Feb. 22, 1971, said laterapplication now abandoned.

BACKGROUND OF THE INVENTION (a) Statement Of The Invention The presentinvention relates to chemically joined, phase separated thermoplasticgraft copolymers and novel macromolecular monomers useful in thepreparation of the graft copolymers.

(b) Description Of The Prior Art lent structural integrity; and,accordingly, have acquired increasing commercial acceptance as materialsfor competing with metals and ceramics. As one example, polyethylene hasbeen regarded as one of the most important polymers among the majorplastics, with its production reaching about 6 billion pounds in 1970(1.7 billion pounds of high density linear polyethylene and 4.3 billionpounds of low density polyethylene).

Despite the widespread use of this important plastic, its use has beenlimited to flexible, translucent, molded articles or flexible, clearfilms, due to its softness. The uses of polyethylene have also beenlimited due to its poor adhesion to many substrates and its low heatdistortion, rendering it unsuitable for many high temperatureapplications.

Attempts by prior art workers to combine the properties of polyolefinsand other polymers by either chemical or mechanical means generally hasresulted in a sacrifice of many of the beneficial properties of both thepolyolefin and the additional polymer. For example, graft copolymers ofpolyethylene and polypropylene have been prepared only with difficultydue to the inertness these polymers have with many other polymerizablemonomers and polymers. The resultant graft copolymer generally has beena mixture which also contains free homopolymers.

Polyblends of a polyolefin with another polymer prepared by blendingquantities of the two polymers together by mechanical means have beengenerally unsuitable for many applications due to their adversesolubility or extractability properties when used with various solventsystems, particularly when containing a rubbery, amorphous component.

The above considerations recognized by those skilled in the art withrespect to the incompatibility of polyolefins with other polymers findalmost equal applicability in the case of other plastics such as thepolyacrylates, polymethacrylates, polyvinylchlorides, etc. Thus, theincompatibility of both natural and synthetic polymers becomesincreasingly apparent as more and more polymers having particularly goodproperties for special uses have become available, and as efforts havebeen made to combine pairs of these polymers for the purpose ofincorporating the different, good properties of each polymer into oneproduct. More often than not, these efforts have been unsuccessfulbecause the resulting blends have exhibited an instability, and in manycases the desirable properties of the new polymers were completely lost.As a specific example, polyethylene is incompatible with polystyrene anda blend of the two has poorer physical properties than either of thehomopolymers. These failures were at first attributed to inadequatemixing procedures, but eventually it was concluded that the failureswere due simply to the inherent incompatibilities. Although it is nowbelieved that this is a correct explanation, the general nature of suchincompatibility has remained somewhat unclear, even to the present.Polarity seems to be a factor, i.e., two polar polymers are apt to bemore compatible than a polar polymer and a non-polar polymer. Also, thetwo polymers must be structurally and compositionally somewhat similarif they are to be compatible. Still further, a particular pair ofpolymers may be compatible only within a certain range of relativeproportions of the two polymers; outside that range they areincompatible.

Despite the general acceptance of the fact of incompatibility of polymerpairs, there is much interest in devising means whereby the advantageousproperties of combinations of polymers may be combined into one product.

One way in which this objective has been sought involves the preparationof block or graft copolymers. In this way, two different polymericsegments, normally incompatible with one another, are joined togetherchemically to give a sort of forced compatibility. In such a copolymer,each polymer segment continues to manifest its independent polymerproperties. Thus, the block or graft copolymer in many instancespossesses a combination of properties not normally found in ahomopolymer or a random copolymer.

Recently, US. Pat. No. 3,235,626 to Waack, assigned to Dow ChemicalCompany, described a method for preparing graft copolymers of controlledbranch configuration. It is described that the graft copolymers areprepared by first preparing a prepolymer by reacting a vinyl metalcompound with an olefinic monomer to obtain a vinyl terminatedprepolymer. After protonation and catalyst removal, the prepolymer isdissolved in an inert solvent with a polymerization catalyst and isthereafter reacted with either a different polymer having a reactivevinyl group or a different vinyl monomer under free-radical conditions.

The current limitations on the preparation of these copolymers aremechanistic. Thus, there is no means for controlling the spacing of thesidechains along the backbone chain and the possibility of thesidechains having irregular sizes. Due to the mechanistic limitations ofthe prior art methods, i.e., the use of an alpha-olefin terminatedprepolymer with acrylonitrile or an acrylate monomer, complicatedmixtures of free homopolymers result.

In view of the above considerations, it would be highly desirable todevise a means for preparing graft copolymers wherein the production ofcomplicated mixtures of free homopolymers is minimized and thebeneficial properties of the sidechain and backbone polymer are combinedin one product.

Moreover, it is recognized and documented in the literature, such as R.Waack et a1, Polymer, vol. 2, pp. 365-366 (1961), and R. Waack et al.,J. Org. Chem., vol. 32, pp. 3395-3399 (1967), that vinyl lithium is oneof the slowest anionic polymerization initiators. The slow initiatorcharacteristic of vinyl lithium when used to polymerize styrene producesa polymer having a broad molecular weight distribution due to the ratioof the overall rate of propagation of the styryl anion to that of thevinyl lithium initiation. In other words, the molecular weightdistribution of the polymer produced will be determined by the effectivereactivity of the initiator compared with that of the propagatinganionic polymer species, i.e., vinyl lithium initiator reactivitycompared to the styryl anion. Accordingly, following the practice of US.Pat. No. 3,235 626, a graft copolymer having sidechains of uniformmolecular weight cannot be prepared.

US. Pat. Nos. 3,390,206 and 3,514,500 describe proccesses forterminating free-radical and ionic polymerized polymers with functionalgroups which are described as capable of copolymerizing withpolymerizable monomers. The functionally terminated prepolymersdescribed by these patentees also would be expected to have a broadmolecular weight distribution and, therefore, would not be capable ofproducing a chemically joined, phase separated thermoplastic graftcopolymer.

SUMMARY OF THE INVENTION The present invention relates to thermoplasticgraft copolymers comprised of copolymeric backbones containing aplurality of uninterrupted repeating units of the backbone polymer andat least one integrally copolymerized moiety per backbone polymer chainhaving chemically bonded thereto a substantially linear polymer whichforms a copolymerized sidechain to the backbone, wherein each of thepolymeric sidechains has substantially the same molecular weight andeach polymeric sidechain is chemically bonded to only one backbonepolymer.

The graft copolymers of the present invention assume a T type structurewhen only one sidechain is copolymerized into the copolymeric backbone.However, when more than one sidechain is copolymerized into the back- 4bone polymer, the graft copolymer may be characterized as having acomb-type structure illustrated in the following manner:

wherein a represents a substantially linear, uniform molecular weightpolymer or copolymer having a sufficient molecular weight such that thephysical properties of at least one of the substantially linear polymersare manifest; b represents a reacted and polymerized end groupchemically bonded to the sidechain, a, which is integrally polymerizedinto the backbone polymer, and c is the backbone polymer havinguninterrupted segments of sufiicient molecular weight such that thephysical properties of the polymer are manifest.

The backbone of the graft copolymers of the present invention preferablycontains at least about 20 uninterrupted recurring monomeric units ineach segment. It has been found that this condition provides the graftcopolymer the properties of the polymer. In other Words, the presence ofsegments containing at least about 20 uninterrupted recurring monomericunits provides the graft copolymers with the physical propertiesattributed to this polymer, such as crystalline melting point (T andstructural integrity.

The backbone polymeric segments of the chemically joined, phaseseparated thermoplastic graft copolymers of the present invention arederived from copolymerizable monomers, preferably the low molecularweight monomers. These copolymerizable monomers include polycarboxylicacids, their anhydrides and amides, polyisocyanates, organic epoxides,including the thioepoxides, urea-formaldehydes, siloxanes, andethylenically unsaturated monomers. A particularly preferred group ofcopolymerizable monomers include the ethylenically-unsat uratedmonomers, especially the monomeric vinylidene type compounds, i.e.,monomers containing at least one vinylidene CH2=(I] group. The vinyltype compounds represented by the formula H CH2=(|3- wherein a hydrogenis attached to one of the free valences of the vinylidene group arecontemplated as falling within the generic scope of the vinylidenecompounds referred to hereinabove.

The copolymerizable monomers useful in the practice of the presentinvention are not limited by the exemplary classes of compoundsmentioned above. The only limitation on the particular monomers to beemployed is their capability to copolymerize with the polymerizable endgroups of the sidechain prepolymer under free-radical, ionic,condensation, or coordination (Ziegler or Ziegler- Natta catalysis)polymerization reactions. As it will be seen from the description ofmarcromolecular monomers, described hereinbelow, the choice ofpolymerizable end groups includes any polymerizable compoundcommercially available. Accordingly, the choice of respectivepolymerizable end group and copolymerizable monomer can be chosen, basedupon relative reactivity ratios under the respective copolymerizationreaction conditions suitable for copolymerization reaction. For example,alpha-olefins copolymerize with one another using Ziegler catalysts, andacrylates copolymerize with vinyl chloride, acrylonitrile and otheralkyl acrylates. Accordingly, an alpha-olefin terminated macromolecularmonomer copolymerizes with ethylene and aIpha-olefins using a Zieglercatalyst and an acrylate 0r methacrylate terminated macromolecularmonomer copolymerizes with vinyl chloride, acrylonitrile,

acrylates and methacrylates under free-radical conditions in a mannergoverned by the respective reactivity ratios for the comonomers.

As will be explained hereinafter, the excellent combination ofbeneficial properties possessed by the graft copolymers of the presentinvention are attributed to the large segments of uninterruptedcopolymeric backbones and the integrally copolymerized linear sidechainsof controlled molecular weight and narrow molecular weight distribution.

The term linear, referred to hereinabove, is being used in itsconventional sense, to pertain to a polymeric backbone that is free fromcross-linking. v

The sidechain polymers having substantially uniform molecular weight arecomprised of substantially linear polymers and copolymers produced byanionic polymerization of any anionically polymerizable monomer, as willbe described hereinafter. Preferably, the sidechain polymer will bedifferent than the backbone polymer.

It is preferred that at least one segment of the sidechain polymer ofthe graft copolymers of the present invention have a molecular weightsuflicient to manifest the beneficial properties of the respectivepolymer. In other words, physical properties of the sidechain polymersuch as the glass transition temperature (T will be manifest. Generally,as known in the art, the average molecular weight of the segment of thepolymeric sidechains necessary to establish the physical properties ofthe polymer will be from about 5,000 to about 50,000.

In light of the unusual and improved physical properties possessed bythe thermoplastic graft copolymers of the present invention, it isbelieved that the monofunctionally bonded polymeric sidechains havingsubstantially uniform molecular weight form what is known as domains.

STATEMENT OF THE INVENTION Briefly, the chemically joined, phaseseparated thermoplastic graft copolymers of the present invention areprepared by first preparing the sidechains in the form of monofunctionalliving polymers of substantially uniform molecular weight. The livingpolymers are thereafter terminated, as by reaction with ahalogen-containing compound that also contains a reactive polymerizablegroup, such as, for example, a polymerizable olefinic or epoxy group, ora compound which contains a reactive site to an anion of the livingpolymer and a polymerizable moiety which does not preferentially reactwith the anion, e.g., maleic anhydride. The monofunctional terminatedliving polymer chains are then polymerized, together with the backbonemonomer, to form a chemically joined, phase separated thermoplasticgraft copolymer wherein the polymeric sidechains are integrallypolymerized into the backbone polymer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The chemically joined, phaseseparated thermoplastic graft copolymers derived from ethylenicallyunsaturated monomers as the backbone comonomer generally correspond tothe following structural formula:

LL L| JL i l L 6 x is a positive integer wherein the terminal methylenegroup in X is either hydrogen, lower alkyl, e.g., methyl, halogen, etc.,and in the case of X, joins the backbone polymer with the sidechainpolymer), a saturated ester wherein R is alkyl or aryl), nitrlle (i.e.,CEN), amide wherein R and R are either hydrogen, alkyl or arylradicals), amine wherein R and R are either hydrogen, alkyl or arylradicals), isocyanate, halogen (i.e., F, Cl, Br or I) and ether (i.e.,OR, wherein 'R is either alkyl or aryl radicals); X and X may be thesame or different. However, in the case where X is an ester, X should bea functional group such as ester, halogen, nitrile, etc., as explainedhereinabove with respect to the respective reactivity ratios of thecomonomers used to prepare the graft copolymers; Y is a substantiallylinear polymer or copolymer wherein at least one segment of the polymerhas a sufiicient molecular weight to manifest the properties of therespective polymer, i.e., a molecular Weight of from about 5,000 toabout 50,000, preferably a molecular weight of from about 10,000 toabout 35,000, more preferably 12,000 to about 25,000; the symbols :1, band c are positive integers, with the proviso that a and b are a valuesuch that the physical properties of the uninterrupted segments in thebackbone, e.g., Tm, are manifest, preferably at least about 20; and thesymbol 0 is at least one, but preferably greater than one, e.g., a valuesuch that the molecular weight of the graft copolymer will be up toabout 2,000,000.

The formation of the graft copolymers of the present invention may bebetter understood by reference to the following reactions illustrated bythe equations set forth below wherein the invention is illustrated interms of polystyrene sidechains and polyethylene backbones. It can beseen from these equations that the first reactions involve thepreparation of living polymers of polystyrene. The living polymers arethereafter reacted with a molar equivalent of allyl chloride, whereinthe reaction takes place at the carbon-chloride bond, rather than at thecarbon-carbon double bond. The vinyl terminated polystyrene, referred toherein as the alpha-olefin terminated macromolecular monomer, is thencopolymerized with ethylene to produce a graft copolymer ofpolyethylene, whereby the vinyl moiety of the polystyrene is integrallypolymerized into the linear polyethylene backbone.

Alternatively, the living polymer can be reacted with an epoxide suchas, for example, ethylene oxide, to produce an alkoxide ion which canthen be reacted with the halogen-containing olefin, i.e., allylchloride, to produce an alpha-olefin terminated macromolecular monomer.This, in essence, places the terminal alphaolefin farther away from thearomatic ring of the polystyrene and therefore reduces any sterichindering influence that might be exerted by the aromatic ring.

FORMATION OF THE GRAFI COPOLYMER OF ALPHA- OLEFIN TERMINATED POLYSTYRENESIDECHAIN AND POLYETHYLENE BACKBONE Termination with Active End Group: iCHZZCH CH2 C1 Graft Copolymerization lxCH CH; Polymerization Catalyst Inthe equations above, the symbols a, b, c, n and x are positive integerswherein a and b are at least about 20, n has a value of from about 50 toabout 500, and x has a value corresponding approximately to the sum of aand b.

Preparation Of The Living Polymers The sidechains of the chemicallyjoined, phase separated graft copolymers, above, are preferably preparedby the anionic polymerization of a polymerizable monomer or combinationof monomers. In most instances, such monomers are those having anolefinic group, such as the vinyl containing compounds, although theolefinic containing monomers may be used in combination with epoxy orthiopoxy containing compounds. The living polymers are convenientlyprepared by contacting the monomer with an alkali metal hydrocarbon oralkoxide salts in the presence of an inert organic diluent which doesnot participate in or interfere With the polymerization reaction.

Those monomers susceptible to anionic polymerization are well-known andthe present invention contemplates the use of all anionicallypilymerizable monomers. Non-limiting illustrative species include vinylaromatic compounds, such as styrene, alpha-methylstyrene, vinyl tolueneand its isomers; vinyl unsaturated amides such as acrylamide,methacrylamide, N,N-dilower alkyl acrylamides, e.g., N,N-dimethylacrylamide; acenaphthalene; 9-acrylcarbazole; acrylonitrile andmethacrylonitrile; organic isocyanates including lower alkyl, phenyl,lower alkyl phenyl and halophenyl isocyanates, organic diisocyanatesincluding lower alkylene, phenylene and tolylene diisocyanates; loweralkyl and allyl acrylates and methacrylates, including methyl, t-butylacrylates and methacrylates; lower olefins, such as ethylene, propylene,butylene, isobutylene, pentene, hexene, etc.; vinyl esters of aliphaticcarboxylic acids such as vinyl acetate, vinyl propionate, vinyl octoate,vinyl oleate, vinyl stearate, vinyl benzoate; vinyl lower alkyl ethers;vinyl pyridines, vinyl pyrrolidones; dienes including isoprene andbutadiene. The term lower is used above to denote organic groupscontaining eight or fewer carbon atoms. The preferred olefiniccontaining monomers are conjugated dienes containing 4 to 12 carbonatoms per molecule and the vinyl-substituted aromatic hydrocarbonscontaining up to about 12 carbon atoms.

Many other monomers suitable for the preparation of the side-chains byanionic polymerization are those disclosed in Macromolecular Review:Volume 2, pages 74- 83, Interscience Publishers, Inc. (1967), entitledMonomers Polymerized by Anionic Initiators, the disclosure of which isincorporated herein by reference.

The initiators for these anionic polymerizations are any alkali metalhydrocarbons and alkoXide salts which produce a mono-functional livingpolymer, i.e., only one end of the polymer contains a reactive anion.Those catalysts found suitable include the hydrocarbons of lithium,sodium or potassium as represented by the formula RMe wherein Me is analkali metal such as sodium, lithium or potassium and R represents ahydrocarbon radical, for example, an alkyl radical containing up toabout 20 carbon atoms or more, and preferably up to about eight carbonatoms, an aryl radical, an alkaryl radical or an aralkyl radical.Illustrative alkali metal hydrocarbons include ethyl sodium, n-propylsodium, n-butyl potassium, n-octyl potassium, phenyl sodium, ethyllithium, secbutyl lithium, t-butyl lithium and 2-ethylhexyl lithium.Sec-butyl lithium is the preferred initiator because it has a fastinitiation which is important in preparing polymers of narrow molecularweight distribution. It is preferred to employ the alkali metal salts oftertiary alcohols, such as potassium t-butyl alkoxylate, whenpolymerizing monomers having a nitrile or carbonyl functional group.

The alkali metal hydrocarbons and alkoxylates are either availablecommercially or may be prepared by known methods, such as by thereaction of a halohydrocarbon, halobenzene or alcohol and theappropriate alkali metal.

An inert solvent generally is used to facilitate heat transfer andadequate mixing of initiator and monomer. Hydrocarbons and ethers arethe preferred solvents. Solvents useful in the anionic polymerizationprocess include the aromatic hydrocarbons such as benzene, toluene,Xylene, ethylbenzene, t-butylbenzene, etc. Also suitable are thesaturated aliphatic and cycloaliphatic hydrocarbons such as n-hexane,n-heptane, n-octane, cyclohexane and the like. In addition, aliphaticand cyclic ether s0lvents can be used, for example, dimethyl ether,diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, anisole,tetrahydropyran, diglyme, glyme, etc. The rates of po lymerization arefaster in the ether solvents than in the hydrocarbon solvents, and smallamounts of ether in the hydrocarbon solvent increase the rates ofpolymerization.

The amount of initiator is an important factor in anionic polymerizationbecause it determines the molecular weight of the living polymer. If asmall proportion of initiator is used, with respect to the amount ofmonomer, the molecular weight of the living polymer will be larger thanif a large proportion of initiator is used. Generally, it is advisableto add initiator dropwise to the monomer (when that is the selectedorder of addition) until the persistence of the characteristic color ofthe organic anion, then add the calculated amount of initiator for themolecular weight desired. The preliminary dropwise addition serves todestroy contaminants and thus permits better control of thepolymerization.

To prepare a polymer of narrow molecular weight distribution, it isgenerally prefered to introduce all of the reactive species into thesystem at the same time. By this technique, polymer growth byconsecutive addition of monomer takes place at the same rate to anactive terminal group, without chain transfer or termination reaction.When this is accomplished, the molecular weight of the polymer iscontrolled by the ratio of monomer to initiator, as seen from thefollowing representation:

Molecular Weight of living polymer Moles of monomer As it can be seenfrom the above formula, high concentrations of initiator leads to theformation of low molecular weight polymers, whereas, low concentrationsof initiator leads to the production of high molecular weight polymers.

The concentration of the 'monomer charged to the reaction vessel canvary widely, and is limited by the ability of the reaction equipment todissipate the heat of polymerization and to properly mix the resultingviscous solutions of the living polymer. Concentrations of monomer ashigh as 50% by weight or higher based on the weight of the reactionmixture can be used. However, the preferred monomer concentration isfrom about to about 25% in order to achieve adequate mixing.

As can be seen from the formula above and the foregoing limitations onthe concentration of the monomer, the initiator concentration iscritical, but may be varied according to the desired molecular weight ofthe living polymer and the relative concentration of the monomer.Generally, the initiator concentration can range from about 0.001 toabout 0.1 mole of active alkali metal per mole of monomer, or higher.Preferably, the concentration of the initiator will be from about 0.01to about 0.004 mole of active alkali metal per mole of monomer.

The temperature of the polymerization will depend on the monomer.Generally, the reaction can be carried out at temperatures ranging fromabout 100 C. up to about 100 C. When using aliphatic and hydrocarbondiluents, the preferred temperature range is from about l0 C. to about100 C. With ethers as the solvent, the preferred temperature range isfrom about 100" C. to about 100 C. The polymerization of the styrene isgenerally carried out at slightly above room temperature; thepolymerization of alpha-methylstyrene preferably is carried out at lowertemperatures, e.g., 80 C.

The preparation of the living polymer can be carried out by adding asolution of the alkali metal hydrocarbon initiator in an inert organicsolvent to a mixture of monomer and diluent at the desiredpolymerization temperature and allowing the mixture to stand with orwithout agitation until the polymerization is completed. An alternativeprocedure is to add monomer to a solution of the catalyst in the diluentat the desired polymerization tempera- 10 ture at the same rate that itis being polymerized. By either method the monomer is convertedquantitatively to a living polymer as long as the system remains free ofimpurities which inactivate the anionic species. As pointed out above,however, it is important to add all of the reactive ingredients togetherrapidly to insure the formation of a uniform molecular weightdistribution of the polymer.

The anionic polymerization must be carried out under carefullycontrolled conditions, so as to exclude substances which destroy thecatalytic eifect of the catalyst or initiator. For example, suchimpurities as water, oxygen, carbon dioxide, and the like. Thus, thepolymerizations are generally carried out in dry equipment, usinganhydrous reactants, and under an inert gas atmosphere, such asnitrogen, helium, argon, methane, and the like.

The above-described living polymers are susceptible to further reactionsincluding further polymerization. Thus, if additional monomer, such asstyrene, is added to the living polymer, the polymerization is renewedand the chain grows until no more monomeric styrene remains.Alternatively, if another different anionically polymerizable monomer isadded, such as butadiene or ethylene oxide, the above-described livingpolymer initiates the polymerization of the butadiene or ethylene oxideand the ultimate living polymer which results consists of a polystyrenesegment and a polybutadiene or polyoxyethylene segment.

A poly(styrene-ethylene) block copolymer can be prepared by contactingliving polystyrene with ethylene in the presence of a compound of atransition metal of Group V-VIII in the periodic table, e.g., titaniumtetrachloride. This technique is also applicable to the alphaolefins,such as propylene. The resulting copolymer is still a living polymer andcan be terminated by the methods in accordance to the practice of thepresent invention.

As noted above, the living polymers employed in the present inventionare characterized by relatively uniform molecular weight, i.e., thedistribution of molecular weights of the mixture of living polymersproduced is quite narrow. This is in marked contrast to the typicalpolymer, where the molecular weight distribution is quite broad. Thedifference in molecular weight distribution is particularly evident froman analysis of the gel permeation chromatogram of commercial polystyrene(Dow 666u) prepared by free-radical polymerization and polystyreneproduced by the anionic polymerization process utilized in accordancewith the practice of the present invention.

Production Of The Macromolecular Monomers By Termination Of The LivingPolymers The living polymers herein are terminated by reaction with ahalogen-containing compound which also contains a polymerizable moiety,such as an olefinic group or an epoxy or thioepoxy group. Suitablehalogen-containing terminating agents include: the vinyl haloalkylethers wherein the alkyl groups contain six or fewer carbon atoms suchas methyl, ethyl, propyl, butyl, isobutyl, secbutyl, amyl or hexyl;vinyl esters or haloalkanoic acids wherein the alkanoic acid containssix or fewer carbon atoms, such as acetic, propanoic, butyric,pentanoic, or hexanoic acid; olefinic halides having six or fewer carbonatoms such as vinyl halide, allyl halide, methallyl halide,6-halo-1-hexene, etc; halides of dienes such as2-halomethyl-1,3-butadiene, epihalohydrins, acrylyl and methacrylylhalides, haloalkylmaleic anhydrides; haloalkylmaleate esters; vinylhaloalkylsilanes; vinyl haloaryls; and vinyl haloalkaryls, such asvinylbenzyl chloride (VBC); haloalkyl norbornenes, such as bromoethylnorb ornene, bromonorbornane, and epoxy compounds such as ethylene orpropylene oxide. The halo group may be chloro, fluoro, bromo, or iodo;preferably, it is chloro. Anhydrides of compounds having an olefinicgroup or an epoxy or thioepoxy group may also be employed, such asmaleic anhydride, acrylic or methacrylic anhydride. The followingequations illustrate the typical termination reactions in accordancewith the practice of the present invention:

In the above equations, R, R R R and R are each selected from the groupconsisting of hydrogen and lower alkyl, and aryl radicals. Preferably, Rwill be lower alkyl, such as sec-butyl; R wil be either hydrogen ormethyl; R will be phenyl; R will be hydrogen or lower alkylene radical;and R will be either hydrogen or lower alkyl radical. The symbol n is apositive integer such that the properties of the polymer are manifest,i.e., a value such that the polymer will have a molecular Weight in therange of from about 5,000 to about 50,000, preferably a molecular weightin the range of from about 10,000 to about 35,000, more preferably amolecular weight in the range of from about 12,000 to about 25,000.

Termination of the living polymer by any of the above types ofterminating agents is accomplished simply by adding the terminatingagent to the solution of living polymer at the temperature at which theliving polymer is prepared. Reaction is immediate and the yield istheoretical. A slight molar excess of the terminating agent, withrespect to the amount of catalyst, may be used although the reactionproceeds on a mole-for-mole basis.

The termination may be conducted in any suitable inert solvent.Generally, it is advisable to utilize the same solvent system employedin the preparation of the living polymer. A preferred embodiment of theinvention comprises conducting the termination reaction in a hydrocarbonsolvent rather than the polar ether type solvents such astetrahydrofuran. It has been found that the hydrocarbon solvents such asthe aromatic hydrocarbons, saturated aliphatic and cycloaliphatichydrocarbons cause several differences in the reaction conditions andthe resulting product. For example, the termination reaction can beconducted at higher temperatures wtih hydrocarbon solvents as opposed tothe ether solvents.

In some instances, because of the nature of the living polymer and themonomer from which it is prepared, or because of the nature of theterminating agent, certain deleterious side reactions occur which resultin an impure product. For example, the carbanion of some living polymershave a tendency to react with functional groups or any active hydrogensof the terminating agent. Thus, for example, acrylyl or methacrylylchloride while they act as terminating agents because of the presence ofthe chlorine atom in their structure, they also provide a carbonyl groupin the terminated polymer chain, and this carbonyl group may provide acenter for attack by a second highly reactive living polymer. Theresulting polymer either has twice the expected molecular weight orcontains some chlorine, indicating that some of the living polymer hasbeen terminated by reaction with a second living polymer or with one ofthe active hydrocarbons of the acrylyl or methacrylyl chloride.

It has been discovered that one means for overcoming the foregoingproblem is to render the reactive carbanion less susceptible to reactionwith the functional groups or any active hydrogens of a terminatingagent. A preferred method to render the living polymer less susceptibleto the adverse reaction is to cap the highly reactive living polymerwith a lesser reactive reactant. Examples of some preferred cappingagents include the lower alkylene oxides, i.e., one having eight orfewer carbon atoms such as ethylene and propylene oxide; diphenylethylene, etc. The capping reaction yields a product which still is aliving polymer, but yields a purer product when sub sequently reactedwith a terminating agent containing a functional group or activehydrogen.

It has been found that diphenyl ethylene is an excellent capping agentWhen terminating agents such as, for example, vinyl chloroalkanoates areemployed.

A particularly preferred capping agent is an alkylene oxide, such asethylene oxide. It reacts with the living polymer, with the destructionof its oxirane ring. The following is a typical illustration of thecapping reaction which shows the reaction of ethylene oxide as a 13capping agent with a living polymer prepared by the polymerization ofstyrene with sec-butyl lithium as the initiator:

The capping reaction is carried out quite simply, as in the case of theterminating reaction, by adding the capping reactant to the livingpolymer at polymerization temperatures. The reaction occurs immediately.As in the case of the termination reaction, a slight molar excess of thecapping reactant with respect to the amount of initiator may be used.The reaction occurs on a mole-formole basis.

It will be understood that when a large molar excess of alkylene oxideis reacted with the living polymer, a living polymer having twopolymeric blocks is produced. A typical example with polystyrenesegments and polyoxyalkylene segments is illustrated as follows:

wherein x is a positive integer.

Either of the above-described ethylene oxide capped polymers can beconveniently terminated with a compound containing a moiety reactivewith the anion of the capped polymer and a polymerizable end group,including the following typical compounds: acrylyl chloride, methacrylylchloride, vinyl-2-chloroethyl ether, vinyl chloroacetate,chloromethylmaleic anhydride and its esters, maleic anhydride (yieldshalf ester of maleic acid following protonation with water), allyl andmethallyl chloride and vinylbenzyl chloride.

The reaction of the above-described capped living polymers with eitheracrylyl or methacrylyl chloride can be represented by the followingreaction:

H sec-Bu CHr-CH (CH;CH10);CH;CHgOC f=CHz LiCl wherein n is a positiveinteger of about at least 50, x is either or a positive integer and R iseither hydrogen or methyl.

When an epihalohydrin is used as the terminating reagent, the resultingpolymer contains a terminal epoxy group. This terminal epoxy may be usedas the polymerizable group itself, such as in the preparation of apolyisobutylene or a polypropylene oxide backbone graft co- 14 polymeror may be converted to various other useful polymerizable end groups byany one of several known reactions.

As one embodiment of the invention, the terminated polymer containing anepoxy or thioepoxy end group may be reacted with apolymerizable'carboxylic acid halide, such as acrylic, methacrylic, ormaleic acid halide, to produce a beta-hydroxyalkyl acrylate,methacrylate or maleate ester as the polymerizable terminal moiety ofthe substantially uniform molecular weight polymer. These samepolymerizable esters may be prepared from the terminal epoxy polymer byfirst converting the epoxy group to the corresponding glycol by warmingthe polymer with aqueous sodium hydroxide, followed by conventionalesterification of the glycol end group with the appropriatepolymerizable carboxylic acid, or acid halide.

The resulting glycol obtained by the aqueous hydrolysis of the epoxygroup in the presence of a base may be converted to a copolymer byreaction with a high molecular weight dicarboxylic acid which may beprepared, e.g., by the polymerization of a glycol or diamine with amolar excess of phthalic anhydride, maleic anhydride, succinicanhydride, or the like. These reactions can be modified to obtain apolystyrene block and a polyamide block (Nylon). The glycol terminatedpolymer may also be reacted with a diisocyanate to form a polyurethane.The diisocyanate may be e.g., the reaction product of a polyethyleneglycol having an average molecular weight of 400 with a molar excess ofphenylene diisocyanate.

In another embodiment of the invention, an organic epoxide iscopolymerized with a terminated polymer containing an epoxy or thioepoxyend group. The graft copolymer which results is characterized by abackbone having uninterrupted segments of at least about 20, andpreferably at least about 30, recurring units of the organic epoxide.Preferred organic epoxides include ethylene oxide, propylene oxide,butylene oxide, hexylene oxide, cyclohexene epoxide and styrene oxide,i.e., those having 8 or fewer carbon atoms.

When a haloalkylmaleic anhydride or haloalkylmaleate ester is used asthe terminating agent, the resulting terminal groups can be converted byhydrolysis to carboxyl groups. The resulting dicarboxylic polymer may becopolymerized with glycols or diamines to form polyesters and polyamideshaving a graft copolymer structure.

If it is desired to isolate and further purify the macromolecularmonomer from the solvent from which it was prepared, any of the knowntechniques used by those skilled in the art in recovering polymericmaterials may be used. These techniques include: (1) solvent-non-solventprecipitation; (2) evaporation of solvent in an aqueous media; and (3)evaporation of solvent, such as by vacuum roll drying, spray drying,freeze drying; and (4) steam jet coagulation.

The isolation and recovery of the macromolecular monomer is not acritical feature of the invention. In fact, the macromolecular monomerneed not be recovered at all. Stated otherwise, the macromolecularmonomer, once formed, can be charged with the suitable monomer andpolymerization catalyst to conduct the graft copolymerization in thesame system as the macromolecular monomer was prepared, providing thesolvent and materials in the macromolecular monomer preparation reactordo not poison the catalyst or act in a deleterious manner to the graftcopolymerization process. Thus, a judicious selection of the solvent andpurification of the reactor system in the preparation of themacromolecular monomer can ultimately result in a large savings in theproduction of the graft copolymers of the present invention.

As pointed out above, the macromolecular monomers, which ultimatelybecome the sidechains of the graft copolymers by being integrallypolymerized into the backbone polymer, must have a narrow molecularweight distribution. Methods for determining the molecular weightdistribution of polymers such as the macromolecular monomers are knownin the art. Using these known methods, the weight average molecularweight (MW) and the number average molecular weight (Mn) can beascertained, and the molecular weight distribution (Hw/Hn) for themacromolecular monomer can be determined. The macromolecular monomersmust have nearly a Poisson molecular weight distribution or be virtuallymonodisperse in order to have the highest degree of functionality.Preferably, the ratio of fiw/Hn of the novel macromolecular monomerswill be less than about 1.1. The macromolecular monomers of the presentinvention possess the aforementioned narrow molecular weightdistribution and purity due to the method of their preparation,described hereinabove. Thus, it is important that the sequence of stepsin preparing the macromolecular monomers be adhered to in order toproduce the optimum results in beneficial properties in the graftcopolymers.

Graft Copolymerization Prior to the invention herein, graft copolymerswere prepared by synthesizing a linear backbone, then grafting onto thisbackbone, growing polymeric or preformed polymeric chains. These methodsgenerally require elaborate equipment and produce a mixture of productshaving inferior properties unless further purified. Because of theadditional processing conditions and the use of special equipment, theseprocesses are not economically feasible.

Although some of the prior art graft copolymers, such as those describedin US. Pat. Nos. 3,627,837, 3,634,548 and 3,644,584 and British PatentNos. 873,656 and 1,144,- 151 resemble the graft copolymers of thepresent invention. Generally, the present graft copolymers are differentcompositions, not only because they are prepared by significantlydifferent processes, but because the pendant polymeric chains of thegraft copolymers of this invention are of relatively uniform, minimumlength, and are each an integral part of the backbone. Furthermore, thebackbone of the graft copolymers of the present invention containpolymeric segments of certain minimum length. Thus, the present graftcopolymers differ structurally because the macromolecular monomer isinterposed between polymeric segments of the backbone polymer, ratherthan being merely attached to the backbone polymer in a random manner.These characteristics contribute materially to the advantageousproperties which inhere in these novel graft copolymers.

The graft copolymers of the present invention are prepared by firstsynthesizing the pendant polymeric chains (the polymerizable terminatedliving polymers) then copolymerizing the terminal portions of thepolymeric chains with the second monomer during the formation of thebackbone polymer.

In accordance with the practice of the present invention, thesubstantially pure macromolecular monomers of high controlled molecularweight and molecular weight distribution have an appropriate reactiveend group suitable for any mechanism of copolymerization, e.g.,freeradical, cationic, anionic, Ziegler catalysis, and condensation.Thus, the reactive end group is selected for easy copolymerization withlow cost monomers by conventional means and within existingpolymerization equipment.

The copolymerization with the macromolecular monomers and the secondreactive monomer is a graft-like structure where the pendant chain is apolymer whose molecular weight and distribution are predetermined byindependent synthesis. The distribution of the side-chain polymer alongthe backbone is controlled by the reactivity ratios of the comonomers.

Since the reactive end group of the macromolecular monomer iscopolymerized with the second monomer, it is an integral part of thebackbone polymer. Thus, the polymerizable end group of themacromolecular monois int rposed between large segments of the backbonepolymer.

The present invention provides a means for controlling the structure ofthe graft copolymer. More specifically, the control of the structure ofthe graft copolymer can be accomplished by any one or all of thefollowing means: (1) by determining the reactivity ratio of themacromolecular monomer and a second monomer during the copolymerizationreaction, a pure graft polymer free from contamination by homopolymerscan be prepared; (2) by controlling the monomer addition rates duringthe copolymerization of a macromolecular monomer and a second monomer,the distance between the sidechains in the polymer structure can becontrolled; and (3) the size of the graftchain can be predetermined andcontrolled in the anionic polymerization step of the preparation of themacromolecular monomer.

It will be apparent to those skilled in the art that by the properselection of terminating agents, all mechanisms of copolymerization maybe employed in preparing the controlled phase separated graftcopolymers.

As alluded to hereinabove, the chemically joined, phase separated graftcopolymers of the present invention are preferably copolymerized withany ethylenically-unsaturated monomer including the vinylidene typecompounds containing at least one vinylidene CH group and preferably thevinyl-type compounds containing the characteristic CH =CH group whereinhydrogen is attached to one of the free valences of the vinylidenegroup. The copolymerization, as pointed out above, is only dependentupon the relative reactivity ratios of the terminal group and thecomonomer.

Examples of some of the preferred ethylenically-unsaturated compoundsused as the comonomers include the acrylic acids, their esters, amidesand nitriles including acrylic acid, methacrylic acid, the alkyl estersof acrlylic and methacrylic acid, acrylonitrile, methacrylonitrile,acrylamide, methacrylamide, N,N dimethacrylamide (NNDMA); the vinylhalides such as vinyl chloride, and vinylidene chloride; the vinylcyanides such as vinylidene cyanide (1,1-dicyanoethylene); the vinylesters of the fatty acids such as vinyl acetate, vinyl propionate andvinyl chloroacetate, etc.; and the vinylidene containing dicarboxylicanhydrides, acids and esters, fumaric acid and esters, maleicanhydrides, acids and esters thereof.

A particularly important class of vinylidene type com pounds useful ascomonomers with the alpha-olefin and styrene terminated macromolecularmonomers include the vinyl olefinic hydrocarbons, such as ethylene,propylene, l-butene, isobutylene, l-pentene, l-hexene, styrene,3-methyl-1-butene, 4-methyl-1-hexene and cyclohexene. Also, there may beused as the comonomers the polyolefinic materials containing at leastone vinylidene group such as the butadiene-1,3-hydrocarbons includingbutadiene, isoprene, piperylene and other conjugated dienes, as well asother conjugated and non-conjugated polyolefinic monomers includingdivinyl benzene, the diacrylate type esters of methylene, ethylene,polyethylene glycols, and polyallyl sucrose.

The most preferred ethylenically unsaturated comonomers are thecommercially available and widely used monomers such as methyl acrylate,butyl acrylate, 2-ethyl hexyl acrylate, methyl methacrylate, vinylchloride, vinylidene chloride, vinylidene cyanide, acrylonitrile; andthe hydrocarbon monomers such as ethylene, propylene, styrene; and theconjugated dienes such as butadiene and isoprene.

In addition to the hereinabove described ethylenicallyunsaturatedcomonomers useful in the practice of the invention, there .are includedthe comonomers capable of copolymerizing by condensation orstep-reaction polymerization conditions with the polymerizablemacromolecular monomers of the invention. In this connection, thepolymerizable macromolecular monomers will contain the appropriateterminal groups necessary to facilitate the 17 condensation reaction.For example, living polymers terminated with epichlorohydrin willcontain an epoxy terminal group which converts to a group uponsaponifiaction. This vicinal hydroxy group is capable of copolymerizingwith polybasic acids and anhydrides to form polyesters, such as adipicacid, phthalic anhydride, maleic anhydride, succinic anhydride,trimellitic anhydride, etc., aldehydes to form polyacetals, such aspolyformaldehyde, ureaformaldehydes, acetaldehydes, etc.;polyisocyanates and polyisocyanate prepolymers to form polyurethanes;and siloxanes to form polysiloxanes. The living polymers terminated withhalomaleic anhydride or halomaleate ester may be converted to terminalcarboxyl groups by conventional hydrolysis. The resulting dicarboxylicterminated polymer can be copolymerized with glycols to form polyestersor with diamines to form polyamides having a graft copolymer structure.Alternatively, the maleic anhydride or ester terminal group or thepolymer can be used in the condensation polymerization with the glycolsor diamines. The vicinal hydroxyl or carboxyl terminated polymers of theinvention can also be copolymerized with epoxy compounds, and the iminecompounds, such as ethyleneimine.

The placement of the sidechain in the polymer backbone is dependent onthe terminal group of the macromolecular monomer and the reactivity ofthe comonomer.

The macromolecular monomers of the invention are stable in storage anddo not significantly homopolymerize. Furthermore, the macromolecularmonomer copolymerizes through the terminal double bond or reactive endgroup and is not incorporated into the polymeric backbone by graftingreactions to the polymer of the macromolecular monomer segment.

As indicated hereinabove, the macromolecular monomers of the inventioncopolymerize with commercial vinyl monomers in a predictable manner asdetermined by relative reactivity ratios. It can be shown that theinstantaneous copolymer equation:

when M is in very low molar concentrations.

Thus, the macromolecular monomer (M copolymerization with other monomers(M are described only by r values and monomer feed compositions.Rearrangement of equation (2) gives:

(3) dM /M Percent conversion M 2 T2 (1M M 1 Percent conversion M Thereactivity ratio, r can be estimated from a relatively low conversionsample of a single copolymerization experiment. The validity of thisconcept of a predictable and controllable reactivity of themacromolecular monomer can thereby be established. It has been shownthat the reactivity of commercial monomers with the macromolecularmonomers of the present invention with various end groups correlate withavailable literature values for reactivity ratios of r;,.

The method of the present invention permits the utilization of all typesof polymerizable monomers for incorporation into backbone polymers, andmakes it possible for the first time to design and build graftcopolymers of controlled molecular structure, and of backbone and graftsegments with different properties, such as hydrophobic and hydrophilicsegments, crystalline and amorphous segments, polar and non-polarsegments, segments with widely different glass transition temperatures,whereas prior 18 work on SDS terblock copolymers had been limited to theincompatibility of glassy polystyrene blocks with rubbery polydieneblocks.

The copolymerization of the polymerizable macromolecular monomers withthe comonomers may be conducted in a wide range of proportions.Generally speaking, a sufiicient amount of the macromolecular monomershould be present to provide the chemically joining of at least one ofthe uniform molecular weight sidechain polymers to each backbonepolymer, so that a noticeable effect on the properties of the graftcopolymcric properties can be obtained. Since the molecular weight ofthe polymerizable macromolecular monomer generally exceeds that of thepolymerizable comonomers, a relatively small amount of the polymerizablemacromolecular monomer can be employed. However, the chemically joined,phase separated thermoplastic graft copolymers may be prepared bycopolymerizing a mixture containing up to about by weight, or more, ofthe polymerizable macromolecular monomers of this invention, althoughmixtures containing up to about 60% by weight of the polymerizablemacromolecular monomer are preferred. Stated otherwise, the resinousthermoplastic chemically joined, phase separated graft copolymer of theinvention is comprised of 1) from 1% to about 95 by weight of thepolymerizable macromolecular monomer having a narrow molecular weightdistribution (i.e., a Ww/rlTn, of less than about 1.1), and (2) from 99%to about 5% by weight of a copolymerizable comonomer definedhereinabove.

The polymerizable macromolecular monomers copolymerize with thehereinabove referred to comonomers in bulk, in solution, in aqueoussuspension and in aqueous emulsion systems suitable for the particularpolymerizable macromolecular monomer, its end group and the copolymeremployed. If a catalyst is employed, the polymerization environmentsuitable for the catalyst should be employed. For example, oilorsolvent-soluble peroxides such as benzoyl peroxides, are generallyeffective when the polymerizable macromolecular monomer is copolymerizedwith an ethylenically unsaturated comonomer in bulk, in solution in anorganic solvent such as benzene, cyclohexane, hexane, toluene, xylene,etc., or in aqueous suspension. Water-soluble peroxides such as sodium,potassium, lithium and ammonium persulfates, etc. are useful in aqueoussuspension and emulsion systems. In the copolymerization of many of thepolymerizable macromolecular monomers, such as those with anethylenicallyunsaturated end group and a polystyrene, polyisoprene orpolybutadiene repeating unit, an emulsifier or dispersing agent may beemployed in aqueous suspension systems. In these systems, particularadvantage can be achieved by dissolving the water-insolublepolymerizable macromolecular monomer in a small amount of a suitablesolvent, such as a hydrocarbon. By this novel technique, the comonomercopolymerizes with the polymerizable macromolecular monomer in thesolvent, in an aqueous system surrounding the solvent-polymer system. Ofcourse, the polymerization catalyst is chosen such that it will besoluble in the organic phase of the polymerization system.

As previously stated, various different catalyst systems can be employedin the present invention for the copolymerization process. It will beapparent to those skilled in the art that the particular catalyst systemused in the copolymerization will vary, depending on the monomer feedand the particular end group on the macromolecular monomer. For example,when using a macromolecular monomer having a vinyl acetate end group,best results are generally obtained by employing free-radical catalystsystems. On the other hand, copolymerization utilizing isobutylenemonomer feed with either an allyl,.methallyl or epoxy terminatedmacromolecular monomer, best results are accomplished by utilizing thecationic polymerization techniques. Since the particular polymerizableend group on the macromolecular monomer will depend on the comonomerfeed employed because of the relative reac- 1Q tivity ratios, thepolymerization mechanism commonly employed for the particular comonomerwill be used. For example, ethylene polymerizes under free-radical,cationic and coordination polymerization conditions; propylene andhigher alpha-olefins only polymerize under coordination polymerizationconditions; isobutylene only polymerizes under cationic polymerizationconditions; the dienes polymerize by free-radical anionic andcoordination polymerization conditions; styrene polymerizes underfreeradical, cationic, anionic and coordination conditions; vinylchloride polymerizes under free-radical and coordination polymerizationconditions; vinylidene chloride polymerizes under free-radicalpolymerization conditions; vinyl fluoride polymerizes under free-radicalconditions; tetrafluoroethylene polymerizes under free-radical andcoordination polymerization conditions; vinyl ethers polymerize undercationic and coordination polymerization conditions; vinyl esterspolymerize under free-radical polymerization conditions; acrylic andmethacrylic esters polymerize under free radical, anionic andcoordination polymerization conditions; and acrylonitrile polymerizesunder free-radical, anionic and coordination polymerization conditions.

It will be understood by those skilled in the art that the solvent,reaction conditions and feed rate will be partially dependent upon thetype of catalyst system utilized in the copolymerization process. One ofthe considerations, of course, Will be that the macromolecular monomerbe dissolved in the solvent system utilized. It is not necesary,however, for the monomer feed to be soluble in the solvent system.Generally, under these conditions during the formation of the copolymer,the graft copolymer will precipitate out of the solvent wherein it canbe recovered by techniques known in the polymer art.

The temperature and pressure conditions during the copolymerizationprocess will vary according to the type of catalyst system utilized.Thus, in the production of low density polyolefin backbones underfree-radical conditions, extremely high pressures will be employed. Onthe other hand, the high density substantially linear polyolefinbackbone polymers produced by the coordination type catalyst generallywill be prepared under moderately low pres-. sures.

When preparing graft copolymers having a polyolefin backbone of ethyleneor propylene or copolymers of ethylene and propylene together with amacromolecular monomer, it is preferred to employ a coordinationcatalyst known in the art as the Zeigler catalyst and Natta catalysts(the latter being commonly used for polypropylene). That is, materialsadvanced by Professor-Dr. Karl Ziegler of the Max Klanck Institute ofMulheim, Ruhr, Germany, and Dr. Giulio Natta of Milan, Italy. Some ofthese catalysts are disclosed in Belgian Pat. No. 533,362, issued May16, 1955, and US. Pat. Nos. 3,113,- 115 and 3,257,332 to Ziegler et al.These catalysts are prepared by the interaction of a compound oftransition metals of Group IV-VIII in the periodic table, the cata lyst,and an organometallic compound derived from Group I-III metals, as aco-catalyst. The latter are compounds such as metal hydrides and alkylscapable of giving rise to hydride ions' or carbanions, such as trialkylaluminum. Compounds of the transition elements have a structure withincomplete d-shells and in the lower valence state, can associate withthe metal alkyls to form complexes with highly polarized bonds. Thoseelements hereinabove referred to as the catalysts are preferablytitanium, chromium, vanadium, and zirconium. They yield the best Zieglercatalysts by reaction of their compounds With metal alkyls.

As previously stated, the solvent system utilized will most convenientlybe the solvent employed in the preparation of the macromolecularmonomer. Solvents useful for the polystyrene macromolecular monomers arethose which dissolve polystyrene. Typical solvents for polystyreneinclude cyclohexane, benzene, toluene, xylene, decalin, tetralin, etc.

The copolymerization reaction may be conducted at any suitabletemperature depending on the particular catalyst, macromocular monomer,monomer feed, resulting graft copolymer and solvent used. Generally, thegraft copolymerization will be conducted at a temperature of from about10 C. to about 100 C., preferably from about 20 C. to about 100 C.

The graft copolymerization reaction is preferably conducted by placing apredetermined amount of the macromolecular monomer dissolved in theappropriate solvent in the reactor. The polymerization catalyst andmonomer are thereafter fed into the solvent system to produce the graftcopolymer.

It is generally desirable to provide a graft copolymer having at leastabout 2% macromolecular monomer incorporated in the backbone polymericmaterial, however, satisfactory results can be obtained with up to about40% by weight macromolecular monomer incorporation. Preferably, thegraft copolymers of the present invention will have about 5% to about20% by weight incorporation of the macromolecular monomer into thebackbone polymeric material to obtain the optimum physical properties ofboth the sidechain polymer and the backbone polymer. However, graftcopolymers having up to about 95% by weight of the macromolecularmonomers incorporated therein may be prepared and are contemplatedwithin the scope of the invention.

The means for providing the proper amount of incorporation of themacromolecular monomer can be determined simply by adding theappropriated weighed macromolecular monomer used in the copolymerizationprocess. For example, if a graft copolymer having 10% by Weightincorporation of the macromolecular monomer into the backbone polymer isdesired, one simply employs 10 parts by weight of the macromolecularmonomer for each parts by weight of the monomer feed.

Following the procedures outlined above, graft copolymers having uniquecombinations of properties are produced. These unique combinations ofproperties are made possible by the novel process herein which forcesthe compatibility of otherwise incompatible polymer segments. Theseincompatible segments segregate into phases of their own kind.

The chemically joined, phase separated graft copolymers of the inventionmicroscopically possess a controlled dispersion of the macromolecularsidechain in one phase (domain) within the backbone polymer phase(matrix). Because all of the macromolecular monomer sidechain domainsare an integral part or interposed between large segments of thebackbone polymer, the resulting graft copolymer will have the propertiesof a cross-linked polymer, if there is a large difference in the Tg orTm of the backbone and sidechain segments. This is true only up to thetemperature required to break the thermodynamic cross-link of thedispersed phase. In essence, a physically cross-linked (as opposed tochemical cross-linked) type polymer can be made that is reprocessableand whose properties are established by simple cooling, rather thanvulcanization or chemical cross-linking.

The graft copolymers of the present invention are differentiated fromthe macroscopic opaque and weak blends of incompatible polymers of theprior art. The graft copolymers of this invention contain separatephases which are chemically joined and the dispersion of one segmentinto the matrix polymer is on a microscopic level and below thewavelength of light of the matrix polymer. The graft copolymers hereinare, therefore, transparent, tough, and truly thermoplastic.

An illustrative example of the present invention includes combining theadvantageous properties of polystyrene with the advantageous propertiesof polyethylene, al though these two polymers normally are incompatiblewith one another and a mere physical mixtur of th polymers has verylittle strength and is not useful. To combine these advantageousproperties in one product, it is necessary that the different polymericsegments be present as relatively large segments. The properties ofpolystyrene do not become apparent until the polymer consistsessentially of at least about 20 recurring monomeric units. This samerelationship applies to the polymeric segments present in the graftcopolymers herein, i.e., if a graft copolymer comprising polystyrenesegments is to be characterized by the advantageous properties ofpolystyrene, then those polystyrene segments must, individually, consistessentially of at least about 20 recurring monomeric units. Thisrelationship between the physical properties of a polymeric segment inits minimum size is applicable to the polymeric segment of all graftcopolymers herein. In general, the minimum size of a polymeric segmentwhich is associated with the appearance of the physical properties ofthat polymer in the graft copolymers herein is that which consists ofabout 20 recurring monomeric units. Preferably, as noted earlier herein,the polymeric segments both of the copolymeric backbone and thesidechains, will consist essentially of more than about 30 recurringmonomeric units. However, as it is well-known, the highly beneficialproperties of polymers such as polystyrene are generally apparent whenthe polymer has a molecular weight of from about 5,000 to about 50,000,preferably from about 10,000 to about 35,000, more preferably 12,000 toabout 25,000.

The polymeric segments of the graft copolymers of the invention maythemselves be homopolymeric or they may be copolymeric. Thus, a graftcopolymer of this invention may be prepared by the copolymerization ofethylene, propylene, and a terminated polystyrene containing apolymerizable alpha-olefin end group. The uninterrupted polymericsegments of the backbone of such a graft copolymer will be copolymericsegments of ethylene and propylene.

The graft copolymers comprising polymeric segments having fewer thanabout 20 recurring monomeric units are, nevertheless, useful for manyapplications, but the preferred graft copolymers are those in which thevarious polymeric segments have at least about 20 recurring monomericunits.

Although, as indicated, the graft copolymers herein are characterized bya wide variety of physical properties, depending on the particularmonomers used in their preparation, and also on the molecular weights ofthe various polymer segments Within a particular graft copolymer, all ofthese graft copolymers are useful, as tough, flexible, self-supportingfilms. These films may be used as foodwrapping material, paintersdropcloths, protective wrapping for merchandise displayed for sale, andthe like.

Graft copolymers of the macromolecular monomer, polystyrene, withethylene-propylene, isobutylene, or propylene oxide monomers have beenfound to be stable materials that behave like vulcanized rubbers, butare thermoplastic and reprocessable. Thus, an extremely tough, rubberyplastic is obtained Without the inherent disadvantages of a vulcanizedrubber. These copolymerized rubber-forming monomers with themacromolecular monomers of the present invention have the additional useas an alloying agents for dispersing additional rubber for impactplastics.

Just as metal properties are improved by alloying, so are polymerproperties. By adding the appropriate amount of an incompatible materialto a plastic in a microdispersed phase, over-all polymer properties areimproved. A small amount of incompatible polybutadiene rubber correctlydispersed in polystyrene gives high impact polystyrene. The key to thismicrodispersion is a small amount of chemical graft copolymer that actsas a flux for incorporating the incompatible rubber.

In a similar manner, a copolymer of the micromolecular monomer of thepresent invention can be the flux 22 for incorporating or dispersingincompatible polymers into new matrices making possible a whole new lineof alloys, impact plastics, malleable plastics, and easy-t0- processplastics.

The use of the graft copolymers as alloying agents is particularlyexemplified in the case of polyethyelne-polystyrene blends. As it iswell-known, polyethylene and polystyrene are incompatible when blendedtogether. However, when using the graft copolymers of the presentinvention as an alloying agent, the polyethylene and polystyrene phasescan be conveniently joined.

For example, a blend prepared by mixing to 51 parts by weight ofcommercial polyethylene (either low or high density), 10 to 49 parts byweight of commercial polystyrene and 5 to 30 parts by weight of a graftcopolymer of the present invention comprising polystyrene sidechains anda polyethyelne backbone are useful in making automobile parts, such asinner door panels, kick panels, and bucket seat backs, or applianceparts such as television components. Such blends are also useful asstructural foams, sheets and films, containers and lids in packaging,beverage cases, pails, in the manufacture of toys, molded sheets infurniture, hot mold adhesives and computer and magnetic tapes.

The use of the graft copolymers of the present invention as an alloyingagent offers a distinct advantage over the prior art blends, inasmuch asthe plastic blend can be processed with minimized phase separation ofthe polystyrene and polymers in the blend. The strength of the novelblends of the present invention is also improved over the blends of theprior art.

If polystyrene in the macromolecular monomer is replaced by apoly(aIpha-methylstyrene) and is copolymerized with ethylene, a similarpolyblend can be prepared as described above. However, these blends willhave heat stability which will allow the resulting plastics to be usefulin making hot water pipes, sheets in warm areas, and automobile parts,having oxidative stability over rubbercontaining materials. Theseplastics also have utility in preparing reinforced fiberglass andfillers due to their good adhesion to fiberglass. Polyblends ofpoly(alpha-methylstyrene) graft copolymer with large amounts, i.e., 51-90% by weight of poly(alpha-methylstyrene) and 10- 49% polyethylene,exhibit a higher heat distortion, together with high impact strength andhigh modulus. These plastics are useful in various engineeringapplications and in the manufacture of parts for aircraft, auto bodies,recreational vehicles, appliances, gears, bearings, etc.

Another useful blend utilizing the graft copolymers of the presentinvention comprises mixing 10 to 49 parts of low density polyethylene,51 to 91 parts by weight of poly (alpha-methylstyrene) and zero to 30parts by weight of polystyrene and 5 to 30 parts by weight of the graftcopolymer of the present invention comprising polyethylene backbone withpoly(alpha-methylstyrene) or polystyrene sidechains. The blend isextruded in a mill and the resultant plastic is found useful in makingappliances such as coffee makers, humidifiers, high intensity lamps,color television sets, kitchen-range hardware, blenders, mixers, andelectric toothbrushes. These plastics are also useful in preparingrecreational vehicles such as snowmobile parts and helmets; machineparts such as gears, bearings; plumbing parts such as shower heads,valves, fittings and ballcocks; and motor housing, stamping, lawnsprinklers, stereo tape or cartridges, etc.

The reinforcement of plastics by adding glass fibers or other materialsis diflicult to achieve because of poor wetting character of many basicpolymers. The macromolecular monomers of the present invention,particularly those containing reactive polystyrene, have a tendency towet and bond to glass with facility. By proper dispersion of glass in amacromolecular copolymer, it is possible to upgrade the bond between thedispersed phase and glass. Thus, the macromolecular graft copolymers ofthe present invention can also be used as reinforcing adhesion aids toglass fibers.

The invention is illustrated further by the following examples which,however, are not to be taken as limiting in any respect. In each case,all materials should be pure and care should be taken to keep thereacted mixtures dry and free of contaminants. All parts andpercentages, unless expressly stated to be otherwise, are by Weight.

Preparation Of Macromolecular Monomer Sidechains Having UniformMolecular Weight EXAMPLE 1 (a) Preparation Of Polystyrene TerminatedWith Allyl Chloride: A stainless steel reactor is charged with 76.56parts of A.C.S. grade benzene (thiophene-free), which had been pre-driedby Linde molecular sieves and calcium hydride. The reactor is heated to40 C. and 0.015 parts of diphenylethylene is added to the reactor bymeans of a hypodermic syringe. A 12.1% solution of sec-butyl lithium inhexane is added to the reactor portionwise until the retention of apermanent orange-yellow color, at which point an additional 0.885 parts(1.67 moles) of sec-butyl lithium solution is added, followed by theaddition of 22.7 parts (218 moles) of styrene over a period of 44minutes. The reactor temperature is maintained at 36-42 C. The livingpolystyrene is terminated by the addition of 0.127 parts of allylchloride to the reaction mixture. The resulting polymer is precipitatedby the addition of the alpha-olefin terminated polystyrene-benzenesolution into methanol, whereupon the polymer precipitates out ofsolution. The alpha-olefin terminated polystyrene is dried in an aircirculating atmosphere drier at 4045 C. and then in a fluidized bed toremove the trace amounts of methanol. The methanol content afterpurification is parts per million. The molecular Weight of the polymer,as determined by membrane phase osmometry, is 15,400 (theory: 13,400)and the molecular weight distribution is very narrow, i.e., the Hw/Hn isless than 1.05. The macromolecular monomer has the following structuralformula:

formula:

EXAMPLE 2 (a) Preparation Of Poly(alpha-methylstyrene) Terminated WithAllyl Chloride: A solution of 472 grams (4.0 moles) ofalpha-methylstyrene in 2500 ml. of tetrahydrofuran is treated dropwisewith a 12% solution of n-butyl lithium in hexane until the presistenceof a light red color. An additional ml. (0.0383 mole) of this n-butyllithium solution is added, resulting in the development of a bright redcolor. The temperature of the mixture is then lowered to -80 C., andafter 30 minutes at this temperature, 4.5 grams (0.06 mole) of allylchloride is added. The red color disappears almost immediately,indicating termination of the living polymer. The resulting colorlesssolution is poured into methanol to precipitate the alpha-olefinterminated poly(alpha methylstyrene) which is shown by vapor phaseosmometry to have a number average molecular weight of 11,000 (theory:12,300) and the molecular weight distribution is very narrow, i.e., theHw/fin is less than 1.05. The macromolecular monomer produced has thefollowing structural formula:

wherein n has a value such that the molecular weight of the polymer is11,000.

The procedure of paragraph (a) is repeated using, in place of n-butyllithium, a solution of an equivalent amount of potassium t-butylalkoxylate and in place of alpha-methylstyrene, an equivalent amountrespectively of:

(b) 4-vinyl pyridine, terminating with a molar equivalent of allylchloride to produce a polymer having the following structural formula:

(c) metliacrylonitrile, terminating with a molar equivalent ofvinylbenzyl chloride to produce a polymer having the followingstructural formula:

r tn orn ao-ocniocn2@orr:cm

L at

(d) methyl methacrylate, terminating with vinylbenzyl chloride toproduce a polymer having the following structural formula:

(e) N,N-dimethylacrylamide, terminating with p-vinylbenzyl chloride toproduce a polymer having the follow- N(CH3)Z EXAMPLE 3 Preparation OfPolystyrene Terminated With Vinyl Chloroacetate A solution of one dropof diphenyl ethylene in 2500 ml. of cyclohexane at 40 C. is treatedportionwise with a 12% solution of scc-butyl lithium in cyclohexaneuntil the persistence of a light red color, at which point an additional18 ml. (0.024 mole) of the sec-butyl lithium is added, followed by 312grams (3.0 moles) of styrene. The temperature of the polymerizationmixture is maintained at 40 C. for 30 minutes, whereupon the livingpolystyrene is capped by treatment with 8 ml. (0.040 mole) of diphenylethylene, then terminated by treatment with 6 ml. (0.05 mole) of vinylchloroacetate. The resulting polymer precipitated by addition of thecyclohexane solution to methanol and the polymer is separated by toproduce polystyrene terminated with the half ester of maleic acid.

(f) Epichlorohydrin is substituted for metracrylyl chloride to producean epoxy ether terminated polystyrene.

(g) The procedure of (a) is repeated using in place of styrene, anequivalent amount is isoprene and in place of n-butyl lithium anequivalent amount of sec-butyl lithium to produce primarily a rubberycis-l,4-polyisoprene. The low T living polymer is terminated by theaddition of a molar equivalent, based on sec-butyl lithium, ethyleneoxide as a capping agent, followed by a molar equivalent amount of allylchloride to produce a polymer predominantly having the followingstructural formula:

CHzCHz (CH Il CH: CH CIhCH O CH: C H=CH1 EXAMPLE 8 Preparation ofPolystyrene Terminated with Methacrylyl Chloride A stainless steelreactor is charged with 32 gallons of A.C.S. grade benzene(thiophene-free), which had been predried by Linde molecular sieves andcalcium hydride. The reactor is heated to a temperature of between 38-40C. and ml. of diphenyl ethylene is added to the reactor by means of ahypodermic syringe. An 11.4% solution of secondary butyl lithium inhexane is added to the reactor portionwise until the retention of apermanent orangeyellow color is obtained (60 ml.), at which point anadditional 3.44 pounds of the secondary butyl lithium in hexane is addedto the reactor, followed by the addition of 82.5 pounds of purifiedstyrene over a period of 1 hour and 40 minutes. The reactor temperatureis maintained at 3840 C. The living polystyrene is capped by theaddition of 0.28 pounds of ethylene oxide and the reaction solutionchanges from a red-orange color to yellow. The resulting capped livingpolystyrene is thereafter reacted with 260 ml. of methacrylyl chlorideand the solution changes to a very pale yellow color. The methacrylateterminated polystyrene is precipitated by the addition of the polymerbenzene solution into methanol, whereupon the polymer precipitates outof solution. The polymer is dried in an air circulating atmosphere drierat 4045 C. and then is a fluidized bed to remove the trace amounts ofmethanol. The molecular weight of the polymer as determined by membranephase osmometry, is 13,400 and the molecular weight distribution is verynarrow, i.e. the JTW/Hn is less than 1.05.

EXAMPLE 9 Preparation of Polystyrene Terminated with Maleic Anhydride Astainless steel reactor is charged with 2.5 liters of A.C.S. gradebenzene (thiophene-free), which had been predried by Linde molecularsieves and calcium hydride. The reactor is heated to 40 C. and 0.2 ml.of diphenyl ethylene is added to the reactor by means of a hypodermicsyringe. A 12.1% solution of sec-butyl lithium in hexane is added to thereactor portionwise until the retention of a permanent orange-yellowcolor is obtained (0.7 ml.), at which point an additional 22.3 ml. ofsec-butyl lithium solution is added, followed by the addition of 421.7grams of styrene over a period of 16 minutes. The reactor temperature ismaintained at 40-45 C. Five minutes after styrene addition is completed,ethylene oxide is added from a lecture bottle subsurface intermittentlyuntil the solution is water white. One hour after ethylene oxideaddition is complete, 20.55 ml. of maleic anhdyride-benzene solution(the maleic anhydride solution was prepared by dissolving 84 grams ofmaleic anhydride in 550 grams of purified benzene) is added to thecapped living polymer. One after the addition of the maleic anhydridesolution the contents of the reactor are discharged and precipitated 28.in methanol. The maleic half ester terminated polystyrene had amolecular weight of about 14,000, as determined by Gel PermeationChromatography. The polymerizable macromolecular monomer has astructural formula represented as follows:

sec-But 1 cm oH omcH. o o

H00 1 ll EXAMPLE 10 Preparation of Polybutadiene Terminated with AllylChloride C.P. grade 1,3-butadiene (99.0% purity) is condensed andcollected in l-pint soda bottles. These bottles had been oven baked for4 hours at C., nitrogen purged during cooling, and capped with aperforated metal crown cap using butyl rubber and polyethylene filmliners. These bottles containing the butadiene are stored at 10 C. witha nitrogen pressure head (10 p.s.i.) in a laboratory freezer before use.Hexane solvent is charged to the reactors and heated to 50 C., followedby the addition of 0.2 ml. of diphenyl ethylene by way of a syringe.Secondary butyl lithium is added dropwise via syringe to the reactoruntil the red diphenyl ethylene anion color persists for at least about1015 minutes. The reactor temperature is lowered to 0 C., and 328.0grams of butadiene is charged into the polymerization reactor, followedby the addition of 17.4 ml. (0.02187 mole) of a 12% secondary butyllithium solution in hexane, when half of the butadiene charge has beenadded to the reactor. The butadiene is polymerized for 18 hours inhexane at 50 C. Following the polymerization, 400 ml. portions of theanionic polybutadiene solution in the reactor is transferred undernitrogen pressure into capped bottles. Allyl chloride (0.48 ml., 0.00588mole) is injected into each of the bottles. The bottles are clamped inwater baths at temperatures of 50 C. and 70 C. for periods of timeranging up to 24 hours. The samples in each of the bottles are shortstopped with methanol and Ionol solution and analyzed by Gel PermeationChromatography. Each of the samples is water white and the analysis ofthe Gel Permeation Chromatography scans reveals that each of the sampleshad a narrow molecular weight distribution.

Several comparison samples were conducted in bottles coming from thesame lot of living polybutadiene, which were capped with 2-chlorobutane(0.4 ml., 0.00376 mole) as the terminating agent. The resulting polymersterminated with 2-chlorobutane were yellow in color and after standingfor a period of 24 hours at 70 C., appeared to have a broad molecularweight distribution as revealed by the Gel Permeation Chromatographyscan. It is clear that the reaction and reaction product of2-chlorobutane with anionic polybutadiene are different than thereaction and reaction product of allyl chloride and anionicpolybutadiene.

EXAMPLE 11 Preparation Of Methacrylate Terminated Polyisoprene Aone-gallon Chemco glass-bowl reactor is charged with 2.5 liters ofpurified heptane which had been predried by a Linde molecular sieve andcalcium hydride, followed by the addition of 0.2 ml. of diphenylethylene as an indicator and the reactor is sterilized with the dropwiseaddition of tertiary butyl lithium solution (12% in hexane) until theretention of the characteristic light yellow color is obtained. Thereactor is heated to 40 C. and 19.9 ml. (0.025 mole) of a 12% solutionof tertiary butyl lithium in hexane is injected into the reactor viahypodermic syringe, followed by the addition of 331.4 grams (4.86 moles)of isoprene. The mixture is allowed wherein n has a value such that themolecular weight of the polymer is 12,000.

EXAMPLE 4 Preparation of Poly(alpha-methylstyrene) Terminated With VinylChloroacetate A solution of 357 grams (3.0 moles) of alpha-methylstyrenein 2500 ml. of tetrahydrofuran is treated dropwise with a 12% solutionof t-butyl lithium in pentane until the persistence of a light redcolor. Thereupon, an additional 15.0 ml. (0.03 mole) of the z-butylsolution is added, resulting in the development of a bright red color.The temperature of the mixture is then lowered to 80 C., and afterminutes at that temperature, 5.6 ml. of diphenyl ethylene is added. Theresulting mixture is poured into 5.0 ml. (0.04 mole) of vinylchloroacetate and the thus-terminated poly(alpha-methylstyrene) isprecipitated with methanol and separated by filtration. Its numberaverage molecular weight, as determined by vapor phase osmometry, is14,280 (theory: 12,065) and the molecular weight distribution is verynarrow. The macromolecular monomer produced has the following structuralformula:

wherein n has a value such that the molecular weight of the polymer is14,280.

EXAMPLE 5 Preparation Of Polystyrene Terminated With Vinyl-Z-ChloroethylEther A solution of one drop of diphenyl ethylene at 40 C. is treatedportionwise with a 12% solution of t-butyl lithium in pentane until thepersistence of a light red color, at which point an additional 30 ml.(0.04 mole) of the t-butyl lithium solution is added, followed by 312grams 3.0 moles) of styrene. The temperature of the polymerizationmixture is maintained at 40 C. for 30 minutes, whereupon the livingpolystyrene is terminated by treatment with 8 ml. (0.08 mole) ofvinyl-2-chloroethyl ether. The resulting polymer is precipitated byaddition of the benzene solution to methanol and the polymer isseparated by filtration. Its number average molecular weight, asdetermined by vapor phase osmometry, is 7,200 (theory: 7,870) and themolecular weight distribution is very narrow, i.e., the lTIw/Hn is lessthan 1.06. The

macromolecular monomer produced has the following structural formula:

(cnazo onrorr onicnioon=crn wherein n has a value such that themolecular weight of the polymer is 7,200.

EXAMPLE 6 Preparation Of Polystyrene Terminated With Epichlorohydrin Abenzene solution of living polystyrene is prepared in Example 5 andterminated by treatment with 10 grams (0.10 mole) of epichlorohydrin.The resulting terminated polystyrene is precipitated with methanol andseparated by filtration. Its molecular weight, as shown by vapor phaseosmometry, is 8,660 (theory: 7,757) and its number average molecularweight distribution is very narrow. The macromolecular monomer producedhas the following structural formula:

wherein n has a value such that the molecular weight of the polymer is8,660.

EXAMPLE 7 (a) Preparation of Polystyrene Terminated with MethacrylylChloride: To a solution of 0.2 ml. of diphenyl ethylene in 2500 ml. ofbenzene there is added dropwise a 12% solution of n-butyl lithium inhexane until the persist ence of a light reddish-brown color. Anadditional 24 ml. (0.031 mole) of this n-butyl lithium solution isadded, and then, 416 grams (4.0 moles) of styrene, resulting in thedevelopment of an orange color. A temperature of 40 C. is maintainedthroughout by external cooling and by controlling the rate at which thestyrene is added. This temperature is maintained for an additional 30minutes after all of the styrene has been added, and then is lowered to20 C., whereupon 4.4 grams 0.1 mole) of ethylene oxide is added, causingthe solution to become colorless. The living polymer is terminated byreaction with 10 ml. (0.1 mole) of methacrylyl chloride. The resultingpolymer has a number average molecular weight as shown by vapor phaseosmometry of 10,000. The macromolecular monomer has the followingstructural formula:

0 CH CHzCHzCH1 CHz-C H CH CH O a C :CH;

wherein n has a value such that the molecular weight of the polymer is10,000.

(b) Acrylyl chloride is substituted for methacrylyl chloride in theabove procedure to give an acrylic acid ester end group on thepolystyrene chain.

(c) Allyl chloride is substituted for methacrylyl chloride in procedure(a) to produce an allyl ether terminated polystyrene.

(d) Methallyl chloride is substituted for methacrylyl chloride inprocedure (a) to produce methallyl ether terminated polystyrene.

(e) Maleic anhydride is substituted for metacrylyl chloride in procedure(a), followed by protonation with water to stand for one hour at 40 C.and 0.13 mole of ethylene oxide is charged into the reactor to cap theliving polyisoprene. The capped living polyisoprene is held at 40 C. for40 minutes, whereupon 0.041 mole of methacrylyl chloride is charged intothe reactor to terminate the capped living polymer. The mixture is heldfor 13 minutes at 40 C., followed by removal of the heptane solvent byvacuum stripping. Based upon the Gel Permeation Chromatography scans forpolystyrene, the molecular weight of the methacrylate terminatedpolyisoprene by Gel Permeation Chromatography was about 10,000 (theory:13,000). The methacrylate terminated polyisoprene macromolecular monomerhad a structural formula represented as follows:

l- CH:

EXAMPLE 12 Preparation Of Alpha-Olefin Terminated Polyisoprene Aone-gallon Chemco glass-bowl reactor is charged with 2.5 liters ofpurified heptane which had been predried by a Linde molecular sieve andcalcium hydride, followed by the addition of 0.2 ml. of diphenylethylene as an indicator. The reactor and solvent are sterilized by thedropwise addition of tertiary butyl lithium solution (12% in hexane)until the retention of the characteristic light yellow color isobtained. The reactor is heated to 40 C. and 19.03 ml. (0.02426 mole) oftertiary butyl lithium solution is injected into the reactor viahypodermic syringe, followed by the addition of 315.5 grams (4.63 moles)of isoprene. The polymerization is permitted to proceed at 50 C. for 6 6minutes and at this time 2.0 ml. (0.02451 mole) of allyl chloride isadded to the living polyisoprene. The terminated polyisoprene is held at50 C. for 38 minutes, whereupon the polymer is removed from the reactorto be used in copolymerization reactions. The polymer was analyzed byGel Permeation Chromatography and had a very narrow molecular weightdistribution, i.e., an Fw/lTn of less than about 1.06. The theoreticalmolecular weight of the polymer is 13,000. The polymerizablemacromolecular monomer had a structural formula represented as follows:

z CHiGH=CH EXAMPLE 13 Polymerization Of Styrene With Vinyl Lithium To aone gallon Chemco reactor, there is added 2500 ml. of tetrahydrofuranand cooled to 15 C., at which time 6.5 ml. of a 11.2% solution of vinyllithium in tetrahydrofuran (0.2 mole lithium) is added to the reactor,imparting a light tan color to the solution. The vinyl lithium Waspurchased from Alpha Inorganics Ventron of Beverly, Massachusetts, as atwo molar solution in tetrahydrofuran. Analysis of the solution byseveral methods showed that the solution contained 11.2% active lithium.After the vinyl lithium solution is added, a 0.25 mole styrene charge isadded to the reactor via syringe with the observation of a smallexotherm of about 1 C. (the reactor temperature is controlled by liquidnitrogen cooling coils inside the reactor at a temperature of 15 C.).Ten minutes after the styrene is added, 3.6 ml. of water is added to thereactor, resulting in an almost immediate change in color from deeporange-brown to water white and a considerable gas evolution is observed(the internal pressure in the reactor increased from 8 p.s.i.g. to 12p.s.i.g.). A sample is taken from the head space (about 2.5 liters involume) and from the liquid phase at the same time (the two samples areanalyzed and identified as containing large amounts of ethylene). Thestyrene polymer is withdrawn from the reactor and analyzed. The GPCmolecular weight of the polystyrene is 108,000, as measured against thePressure Chemical Company sample 2(b) standard certified as Hu/Mn=1.06,JTlTw=20,800-* -800 and Hn=20,200:i600. Measured against the samestandard, the weight average molecular weight of the polymer is 99,000and the number average molecular weight is 66,000. The polydispersity ofthe polymer is 1.49. Based upon the limiting polydispersity of about1.33 for living polymers, as indicated in Henderson et al.,Macromolecular Reviews, Vol. 3, Interscience Publishers, page 347(196-8), several side reactions obviously occur when using vinyl lithiumas a polymerization initiator. In addition, the broad molecular weightdistribution and the inability to control the molecular weight of thepolymer is indicative that the initiation rate of vinyl lithium isextremely slow. Accordingly, the vinyl lithium initiated polystyrene isnot suitable in the preparation of the graft copolymers of the presentinvention in preparing chemically joined, phase separated graftcopolymers, which have sidechains of controlled and uniform molecularweights.

Attempted copolymerization of the vinyl lithium initiated polystyrenewith methyl methacrylate and acrylonitrile under free-radical conditionsonly results in a mixture of polystyrene and the respective poly(methylmethacrylate) or polyacrylonitrile. Also, attempted co polymerization ofthe alpha-olefin terminated polystyrene of Example 1(a) with methylmethacrylate and acrylonitrile under free-radical conditions onlyresulted in a mixture of homopolymers as determined by IR analysis ofthe benzene and cyclohexane extracts. This result is expected due to theinability of alpha-olefins to polymerize under free-radical conditions.

Preparation of Graft Copolymers Having Macromolecular Monomerslntegrally Polymerized Into The Backbone EXAMPLE 14 Preparation Of GraftCopolymer From Poly(alphamethylstyrene) Macromolecular MonomerTerminated With Allyl Chloride And Ethylene A solution of 20 grams ofpoly(alpha-methylstyrene) macromolecular monomer terminated with allylchloride and having an average molecular weight of 10,000 prepared as inExample 2(a) in ml. of cyclohexane is prepared and treated with 5.5 ml.of 0.645 M (9.1% solution) diethyl aluminum chloride in hexane and 2 ml.of vanadium oxytrichloride, then pressured with ethylene to 30 p.s.i.g.This system is agitated gently for about one hour at 30 C., whereupon apolymeric material precipitates from the solution. It is recovered byfiltration and pressed into a thin transparent film which is tough andflexible.

EXAMPLE 15 (a) Preparation Of Graft Copolymer Having A PolyethyleneBackbone And Polystyrene Sidechains: One gram of the alpha-olefinterminated polystyrene of uniform molecular weight prepared in Example1(a) is dissolved in 1500 ml. of cyclohexane and charged into a 2- literChemco reactor. The reactor is purged with prepurified nitrogen for 30minutes, and 22 ml. of 25% ethylaluminum sesquichloride solution (inheptane) is added. The reaction is pressured to 40 p.s.i. with 20 gramsof ethylene into the solution. Thereafter, 0.1 ml. of vanadiumoxytrichloride is added and the ethylene pressure drops from 40 p.s.i.to 1 p.s.i. in about 1 minute. The reaction is terminated in 3 minutesby the addition of isopropanol. The polymer is recovered by filtrationand slurried with cyclohexane and then with isopropanol. The yield is18.0 grams of a fluffy, white copolymer having a macromolecular monomersidechain content of 5.8%, as determined by I.R. Extraction and analysisof the extracts indicate all of the macromolecular monomer and 17.0grams of the ethylene copolymerized.

(b) The procedure in Example (a) is repeated, ex-v cept that 2.0 gramsof the macromolecular monomer is used instead of 1.0 gram. The yield ofthe Copolymer is 20.5 grams and the macromolecular monomer sidechaincontent, as determined by I.R., is 10%.

EXAMPLE 16 (a) Preparation Of Graft Copolymer Having A PolyethyleneBackbone And Polystyrene Sidechains: A 2- liter Chemco reactor ischarged With 1500 ml. of purified cyclohexane. 20 grams of alpha-olefinterminated polystyrene prepared in Example 1(a) is added and dissolvedin the purified cyclohexane. The reactor is thereafter purged withprepurified nitrogen for one hour with concurrent slow agitation.Ethylene is added to the reactor at the rate of 5 liters per minute to apressure of 5 p.s.i. The contents of the reactor is heated andcontrolled at C., and high speed stirring is started; ethylaluminumsesquichloride (22.8 ml., 25% in heptane) catalyst is injected into thereactor by a hypodermic syringe, followed by the addition of 0.1 ml. ofvanadium oxytrichloride. Polymerization begins immediately and theethylene pressure in the reactor drops to nearly zero in about a minute.At this point, the ethylene rate is reduced to 0.5 liter per minute, andcooling is used to maintain a temperature of 25 C. At the end of onehour, a total of 43 grams of ethylene has been charged into the reactor,and the reactor is full of a fluffy polymer slurry. The reaction isstopped by the addition of 50 ml. of isopropanol to inactivate thecatalyst.

The polymer is recovered by filtration, slurried and boiled in 1.5liters of benzene for one hour, then re-filtered to remove all theunreacted alpha-olefin terminated polystyrene from the copolymer. Thepolymer is then slurried in 1.5 liters of isopropanol and 0.03 gram ofIrganox 1010 anti-oxidant is added and then filtered and dried in avacuum oven at 50 C. The yield is 49. grams of a fluffy, white copolymerhaving an alpha-olefin terminated polystyrene content of 16%, asdetermined by LR. of a pressed film.

(b) Preparation Of Graft Copolymer Having A Polyethylene Backbone AndPoly(alpha-methylstyrene) Sidechains: The macromolecular monomer used toproduce the sidechains is first prepared by repeating the proceduredescribed in Example 2(a), except that in place of the n-butyl lithium,14 ml. (0.0178 mole) of sec-butyl lithium (12% solution in heptane) isused as the initiator. The number average molecular weight, asdetermined by gel permeation chromatography, is 26,000 (theory: 26,500)and the molecular weight distribution is very narrow, i.e., the Hw/JTnis less than 1.05.

Four liters of cyclohexane (Phillips polymerization grade) and 200 gramsof the alpha-olefin terminated poly (aIpha-methylstyrene) macromolecularmonomer produced as described above are charged into a Chemco reactor.The mixture is heated to 70 C. with concurrent stirring to dissolve themacromolecular monomer. The reactor is purged with high purity nitrogenfor one hour with stirring. Ethylene gas is introduced into the reactorto a pressure of'5 p.s.i., followed by 228 ml. of ethylaluminumsesquichloride (25% in heptane) and 1.0 ml. vanadium oxytrichloride.Agitation is increased and polymerization begins immediately, as notedby the pressure in the reactor dropping to nearly zero. T he ethyleneflow rate is adjusted to 5 liters per minute, and the internaltemperature is controlled at 70 C. At the end of one hour, the reactionis terminated by the addition of 500 ml. of isopropanol to inactivatethe catalyst.

The polymer is isolated by centrifugation, slurried with benzene for onehour, and recentrifuged. The copolymer is I12?! ll. in 5 liters ofmethanol and 0.3 gram "of Irganox 1010 for one hour, centrifuged anddried in an oven at 50 C. The yield is 260 grams having an alpha-olefinterminated poly(alpha-methylstyrene) content of 22%, as determined byIR. analysis of a pressed film.

EXAMPLE 17 Preparation Of Graft Copolymer Having An Ethylene- PropyleneCopolymeric Backbone And Polystyrene Sidechains A 2-liter Chemco reactoris charged with 1 /2 liters of dry benzene and 50 grams ofoly(alpha-methylstyrene) terminated with allyl chloride (as prepared inExample 2). The macromolecular monomer is dissolved by stirring andthereafter purged with nitrogen. The reactor is then charged withethylene and propylene gases at the rate of 200 ml./minute and 800mL/minute, respectively, to build-up 10 p.s.i. pressure in the reactor.While maintaining a reaction temperature of 2535 C., 2 ml. of vanadiumoxytrichloride and 4 ml. of ethylaluminum sesquichloride solution (25 inheptane) are added to the reaction mixture by means of syringe toinitiate polymerization. As the polymerization is started, additionalmacromolecular monomer (335 ml. of 10% macromolecular solution) is addedin solution form, i.e., 70 grams of the macromolecular monomer isdissolved in 630 m1. of dry benzene, and pumped in by Micro-Bellowpump.During the reaction, the flow rate of the gases is checked constantly toinsure that the ethylene and propylene feed rate are at the same initiallevel. Additional catalyst, Et Al Cl (27 ml. in 25 heptane) and VOCl(1.8 ml.) is added by syringe during the reaction, as the rate ofpolymerization slowed down, which is observed by a build-up of theinternal pressure in the reactor. After one hour, the polymerization istermined by the addition of 20 ml. of isopropyl alcohol. The product isprecipitated in methanol and 51 grams of a white, rubbery polymer isobtained.

EXJXMPLE 18 Preparation Of Graft Copolymer Having Ethylene-PropyleneCopolymeric Backbone And Polystyrene Sidechains A l-gallon Chemcoreactor is charged with 3 liters of dried cyclohexane and 10 grams ofpolystyrene terminated with allyl chloride (as prepared in Example 1).The solution is purged with nitrogen for 30 minutes. 20 ml. oftrin-hexylaluminum (25%) solution is added, followed by the addition of139.5 grams of propylene to obtain a pressure of 26 p.s.i. and 20.4grams of ethylene to obtain a pressure of 48 p.s.i. Finally, there isadded 0.2 ml. of vanadium oxytrichloride and a drop in pressure isobserved. The polymerization is terminated after 10 minutes by theaddition of 10 ml. of isopropanol.

The terpolymer solution is added slowly, with stirring, to a 4-literbeaker containing methanol to coagulate the polymer. The polymer whichseparated is air dried overnight. To remove the trace of catalystresidue, the gray colored polymer is dissolved in 500 ml. of cyclohexaneand placed in a 2-liter resin flask, together with 1 liter of distilledwater containing 0.1 gram of NaOH, and refluxed at C. for 2 hours. Thecontents are transferred into a 2-liter separatory funnel, and thebottom Water layer is drained. The upper cyclohexane layer is added tomethanol slowly, with stirring, to coagulate the polymer. The recoveredpolymer is dried in a vacuum oven. The unreacted macromolecular monomeris removed from the dried polymer by first dissolving in cyclohexane andadding dropwise to methyl ethyl ketone, with stirring. The terpolymerwhich is insoluble in methyl ethyl ketone is filtered and dried in avacuum oven, and a yield of 52 grams is obtained. The terpolymer hasimproved tensile strength compared to ethylene-propylene copolymers pre-Preparation Of Graft Copolymer Having Polyisoprene Backbone AndPolystyrene Sidechains 500 ml. of dried cyclohexane is charged into areactor, followed by the addition of 100 ml. (68 grams) of freshlydistilled isoprene (Phillips polymerization grade), together with 17grams of polystyrene terminated with allyl chloride (as prepared inExample 1). The reactor is sealed, followed by the addition of 2.5 ml.of tri-n-hexylaluminum solution (25% in heptane) and 0.16 ml. oftitanium tetrachloride with hypodermic syringes. The reactor is agitatedat 55 C. for 16 hours, whereupon the contents of the reactor are slowlypoured, with stirring, into a 4-liter beaker containing 2 liters of a 1%solution of Ionol antioxidant in isopropanol. A tough, rubbery,copolymer is obtained.

EXAMPLE 20 Preparation Of Graft Copolymer Having A Polystyrene BackboneAnd Polyoxyethylene Sidechains Equal parts of the polyoxyethyleneterminated with vinyl-benzyl chloride prepared in Example 1(c) andstyrene monomer are placed in a reactor containing 1,000 ml. of benzene.The reactor is heated to 60 C. and one part by weight ofazobisisobutyronitrile free-radical polymerization catalyst is added.The polymerization is complete in three hours, obtaining a graftcopolymer having hydrophilic-hydrophobic properties. The graft copolymeralso reduces hydrostatic charges and is an alloying agent forpolystyrene and polyoxyethylene.

EXAMPLE 21 Preparation Of Graft Copolymer Having A PolypropyleneBackbone And Cis-1,4-Polyisoprene Sidechains A l-gallon Chemco reactoris charged with 3 liters of heptane and grams of allyl ether terminatedsis-1,4- polyisoprene (as prepared in Example 7( g) The macromolecularmonomer is dissolved by stirring and thereafter the solution is purgedwith nitrogen for 30 minutes. 10 ml. of diethylaluminum chloride (25%solution in heptane) is added, followed by the addition of 0.3 gram ofTiCl 139.5 grams of propylene is added to obtain a pressure of 26 p.s.i.The reactor is heated to 60 C., and polymerization is terminated after18 hours, whereupon the contents of the reactor are slowly poured, withstirring, into a 4-liter beaker containing 2 liters of 1% solution ofIonol antioxidant in isopropanol. The graft copolymer has higher impactproperties than polypropylene homopolymer.

EXAMPLE 22 Preparation Of Graft Copolymer Having PolyisobutyleneBackbone And Polystyrene Sidechains To a solution of 20 grams ofpolystyrene macromer terminater with epichlorohydrin and having anaverage molecular weight of 10,000 in 1,000 ml. of toluene at 70 C.,there is added 80 grams of isobutylene. 45 ml. of boron trichlorideethyl ether complex is added slowly, the temperature being maintained at70 C. throughout. Polymerization occurs as the catalyst is added and iscomplete almost immediately after all of the catalyst has been added.The resulting graft copolymer is obtained by evaporating away thetoluene and washing the residual solid with methanol.

EXAMPLE 23 Preparation Of Graft Copolymer Having PolyisobutyleneBackbone And Polystyrene Sidechains To 1,000 ml. of methyl chloride at-70 C. there is added 10 grams of polystyrene macromer terminated withepichlorohydrin, having an average molecular weight of 10,000. To thisresulting solution maintained at -70 C.,

there is added concurrently and dropwise, a solution of 2 grams ofaluminum chloride in 400 ml. of methyl chloride and grams ofisobutylene. The time required for these additions is one hour and atthe end of this time polymerization is substantially complete. Theresulting insoluble graft copolymer is isolated by evaporation of themethylene chloride. Similar results are obtainable by employing either amethallyl or methacrylyl end group on the polystyrene such as theproduct prepared in Examples 1(b), 7(a) and 7(d).

EXAMPLE 24 (a) Preparation Of Polystyrene Macromolecular Monomer, CappedWith Butadiene And Terminated With Allyl Chloride: 2.5 liters of benzene(thiophene-free) are charged into the reactor and heated to 40 C. 0.2m1. of diphenyl ethylene is added as an indicator and the reactor issterilized with dropwise addition of a 12% solution of sec-butyl lithiumuntil the persistence of an orange-red color. At this point, anadditional 18 ml. (0.024 mole) of sec-butyl lithium solution (12% inhexane), is added, followed by 416 grams (4.0 moles) of styrene. Thetemperature of the polymerization mixture is maintained at 40 C. for 5minutes. Then the living polystyrene is capped with butadiene bybubbling butadiene gas into the reactor until the color of the solutionchanges from dark red to orange. The living polymer is terminated bytreatment with 4.1 ml. (0.05 mole) of allyl chloride. The macromolecularmonomer thus prepared is precipitated with methanol and separated byfiltration. Its number average molecular weight estimated from gelpermeation chromatography is 25,000 (theory: 18,000) and molecularweight distribution is very narrow. The macromolecular monomer producedhas the following structural formula:

CH3 L J...

where m equals 1 or 2.

(b) Preparation Of Graft Copolymer Having A Polyethylene Backbone AndPolystyrene Sidechains: 2 grams of butadiene capped, alpha-olefinterminated polystyrene macromolecular monomer as prepared in Example24(a) above, is dissolved in 1500 ml. of cyclohexane and charged into a2-liter Chemco reactor. The reactor is purged with prepurified nitrogenfor 30 minutes, and 22 ml. of 25% ethylaluminum sesquichloride solution(in heptane) is added. The reactor is pressurized with 21 grams ofethylene to 40 p.s.i. Thereafter, 0.1 ml. of vanadium oxytrichloride isadded and ethylene pressure is dropped from 40 p.s.i. to 1 p.s.i. inabout 1 minute. The reactor is terminated in 3 minutes by the additionof isopropanol. The polymer is recovered by filtration.

It is known that the physical properties of linear high densitypolyethylene are dependent on its extent of crystailinity, molecularweight and molecular weight distribu tion. It is a balance of thesecharacteristics that generally governs the end use properties offabricated items. The graft copolymers of the present invention,particularly those having a polyethylene backbone and polystyrenesidechains, modifies the physical properties of polyethylene withoutaffecting the beneficial crystalline properties of polyethylene.

As it is illustrated in Example 24, sidechain polymers having a high Tg,such as polystyrene can be replaced with low Tg polymers such aspolybutadiene and predominantly cis-polyisoprene. For example, isoprenecan be anionically polymerized with secondary butyl lithium, preferablyto a molecular weight of about 15,000 and terminated with allylchloride. Alternatively, the rubbery living polymer can be capped withan alkylene oxide such as ethylene oxide followed by termination withallyl chloride, methallyl chloride, or methacrylyl chloride to obtainlow Tg macromolecular monomers. The alpha-olefin terminated (allylchloride and anionically polymerized isoprene) can be used to preparesuper impact polyethylene or polypropylene copolymers utilizing knownpolymerization techniques. For example, the alpha-olefin terminatedpolyisoprene referred to above can be copolymerized with ethylene usinga Ziegler type catalyst system or with propylene using a Natta typecatalyst system.

Still another alternative illustrated in the examples includes the useof hydrocarbon monomers which produce rubbery polymers in the backboneof the copolymer. Included among these monomers are isobutylene,butadiene, isoprene, ethylene-propylene comonomers, etc. The physicalproperties of the rubbery backbone polymers are enhanced bycopolymerization or incorporation into the backbone polymer a widevariety of macromolecular monomers, such as linear polymers anionicallypolymerized from styrene, alpha-methylstyrene, ethylene oxide, 4-vinylpyridine, methacrylonitrile, N,N dimethylacrylamide, methylmethacrylate, etc. A preferred example being the macromolecular monomerof Example 24(a) wherein the polystyrene capped with butadiene orisoprene is terminated with either allyl chloride or2-bromomethyl-5-norbornene. The latter end group is particularly usefulin preparing an ethylene-propylene backbone graft copolymer followingthe procedure of Examples 17 and 18.

As it can be seen from the above, the present invention provides aconvenient and economical means for preparing copolymers utilizing alarge variety of hydrocarbon monomers in forming the backbone polymericblocks and a wide variety of anionically polymerizable monomers informing the sidechain polymers. The copolymerization is facilitated by ajudicious selection of the terminal end group on the anionicallypolymerized polymer. Thus, the problem of copolymerizing incompatiblepolymers is solved providing an economical means for preparingcopolymers having a backbone and sidechain polymer designed to fit onesneeds and the particular end product desired.

EXAMPLE 25 Preparation Of Graft Copolymer From Polystyrene TerminatedWith Vinyl-2-Chloroethyl Ether And Ethyl Acrylate To a solution of 18grams of octylphenoxy polyethoxy ethanol (emulsifier) in 300 grams ofdeionized water there is added, while vigorous agitation in a WaringBlender, a solution of 30 grams of the polystyrene product of Example7(a) and 70 grams of ethyl acrylate. The resulting dispersion is purgedwith nitrogen, then heated with stirring at 65 C., whereupon 0.1 gram ofammonium persulfate is added to initiate polymerization. Thereupon, 200grams of ethyl acrylate and 0.5 gram of 2% aqueous ammonium persulfatesolution are added portionwise over a period of three hours, thetemperature being maintained throughout at 65 C. The resulting graftcopolymer emulsion is cast on a glass plate and allowed to dry in air atroom temperature to a flexible self-supporting film. The film is shownto contain polystyrene segments by extraction with cyclohexane whichdissolves polystyrene; the cyclohexane extract on evaporation yields noresidue.

EXAMPLE 26 Preparation Of Graft Copolymer Of Poly(alpha-methylstyrene)Terminated With Vinyl chloroacetate And Butyl Acrylate A solution of 50grams of poly(alpha-methylstyrene) macromer terminated with vinylchloroacetate and having an average molecular Weight of 12,600 and 450grams of butyl acrylate in 1,000 grams of toluene is purged withnitrogen at 70 C., then treated with 1 gram of azobisisobutyronitrile.The temperature is maintained at 70 C. for 24 hours to yield a solutionof graft copolymer which is cast as a film on a glass plate. The driedfilm is slightly tacky and is shown to contain polystyrene segments byextraction with cyclohexane and evaporation of the cyclohexane extract,as above.

EXAMPLE 27 Preparation Of Graft Copolymer Of Polystyrene MacromolecularMonomer Terminated With Methacrylyl Chloride And Ethyl Acrylate Amixture of 21 grams of polystyrene macromolecular monomer terminatedwith methacrylyl chloride and having an average molecular weight of10,000 prepared as in Example 6, 28 grams of ethyl acrylate and 0.035gram of azobisisobutyronitrile is prepared at room temperature and keptfor 18 hours, under nitrogen, at 67 C. The resulting product is a tough,opalescent material which can be molded at C. to give a clear, tough,transparent sheet.

EXAMPLE 28 Homopolymerization 0f Methacrylate Terminated Polystyrene Themethacrylate terminated polystyrene of Example 8 is subjected tohomopolymerization conditions by suspension polymerization as follows:

Aqueous Solution: G. 5% Lemol 42-88 (Polyvinyl alcohol) 3.0 Distilledwater 300.0

Monomer Solution:

Methacrylate terminated polystyrene 20.0 Lauroyl peroxide 0.16 Benzene(thiophene-free) 30.0

The aqueous polyvinyl alcohol solution is charged into a clean quartbottle and sparged with nitrogen for 15 minutes. The methacrylateterminated polystyrene macrolecular monomer solution is added to thebottle and the bottle is capped after flushing with nitrogen for 2minutes. The bottle is placed in a 70 C. bottle polymerization bath for17 hours.

The product is filtered dried, and dissolved in tetrahydrofuran (THF)for Gel Permeation Chromatography (GPC) analysis. No gel is found in theTHF solution. In the GPC chromatogram, the ratio of the area of theunreacted macromolecular monomer peak at 32 counts to the total peakarea showed that 75.9% of the macromolecular monomer remained unreacted.The analysis of the GPC, therefore, reveals that only 24% of themacromolecular monomer reacted, and this conversion resulted only in alow molecular weight polymer.

EXAMPLE 29 Polymerization Of Acrylates In The Presence Of PolystyreneThis example illustrates that a polystyrene does not graft to anacrylate backbone at the polystyrene segment, establishing that themacromolecular monomers of the invention copolymerize with acrylates andother polymerizable monomers though the terminal double bond.

The attempted polymerization was conducted in a Living polystyrenehaving a molecular weight of about 10,000 terminated with methanol.

The materials are charged into the flask and the clear solution isheated under a slow flowof nitrogen for 13 hours at room temperatures of61 C. to 80 C. After completion, the polymer solution has a total solidscontent of 19.6% (theoretical: 20.0%).

The product mixture is precipitated and dissolved in THF for GPCanalysis. The unreacted polystyrene is determined from the area of thepolystyrene peak in the GPC chromatogram of a known sample weightinjected, and using the polystyrene peak area/gram calibration frompolystyrene standards shown in the following Table.

TABLE 1 GPC Determinttion Of Unreacted Polystyrene Wt. Product Injected(Grams) 0.008039 Polystyrene Peak Area (Grams) 0.1778 UnreactedPolystyrene In Injected Sample (Grams) 0.00268 Unreacted Polystyrene InProduct Percent 33.3

Calculated from standard 66.5 g. area/1.000 g. polystyrene.

The above determination shows that the polymer product contained 33.3%unreacted polystyrene. Therefore, little or no grafting of ethylacrylate to polystyrene macromolecular monomer occurred during thepolymerization.

EXAMPLE 30 Preparation Of Graft Copolymer Having Polystyrene SidechainsAnd Poly(butyl acrylate) Backbone The following ingredients are chargedinto a quart bottle which had been washed, dried, capped and flushedwith nitrogen.

Methacrylate terminated polystyrene (prepared by procedure of Example 8,except that Mn: 11,000) 15.0 Butyl acrylate (Rohm & Haas 3480) 45.0 AIBN(VAZO) 0.09 DMSO (reagent grade) 195.0 Benzene (thiophene-free) 195.0

The methacrylate terminated polystyrene is first dissolved in thebenzene/DMSO solution, followed by dissolving the butyl acrylate andVAZO in the solution. The homogeneous solution is introduced into thenitrogen filled bottle via syringe. The bottle is placed in a 67 C.bottle polymerization bath and rotated at 30 r.p.m. Samples are removedby syringe and short stopped with MEHQ at 75 minutes, 120 minutes and210 minutes. At 300 minutes polymerization time, the remainder of thebottle is short stopped with 4 drops 10% MEHQ in ethanol.

The 'butyl acrylate conversions are obtained by total solidsdetermination on portions of the samples. The remainder of the samplesare precipitated in methanol, dried, and dissolved in THF for GPCanalysis. The methacrylate terminated polystyrene has a peak at 31counts on the GPC chromatogram. The GPC chromatograms of products of 75,120, 210 and 300 minutes shows the disappearance of the peak at 31counts. Analysis of the GPC chromatograms revealed that 25.6% of thegraft copolymer is polystyrene and 74.4% is poly('butyl acrylate).

The above procedure is repeated several times using the samemethacrylate terminated polystyrene having a molecular weight of 11,000and a M w/Mn of less than about 1.1, by copolymerizing increased amountsof butyl acrylate, replacing butyl acrylate with ethyl acrylate andmethyl methacrylate. Table 2 below summarizes the results of thesecopolymerizations.

TABLE 2 Compositions of methacrylate terminated polystyrene-acryliccopolymers prepared in DMSO/benzene solution Percent Copolyme r macro-Macrocompomolecular Comonmolecular sition monomer Polymeromer monomer(percent in ization converconvermacro- Comonmonomer time, sion, sion,molecular omer feed 8 hours percent percent monomer) A 50 4. 75 69. 080. 7 53. 9 MMA 25 2 15. 5 10. 3 18. 2 5 48. 3 53. 4 26. 9

MMA 50 2 12. 0 22. 9 65. 6 4. 75 35. 7 32. 0 47. 3

a S11MA=Methaerylate terminated polystyrene 11,000 Mn methaerylateterminal group; EA=Ethyl acrylate; l3A=Butyl acrylate; MMA=Methylmethacrylate.

EXAMPLE 31 Preparation Of Graft Copolymer Having Polystyrene SidechainsAnd Poly(methyl methacrylate) Backbone The following ingredients arecharged into a clear quart bottle, capped, purged with nitrogen, andpolymerized for 17 /2 hours in a 74 C. bottle polymerization bath.

Methacrylate terminated polystyrene (product of Example 8) g 27.5 Methylmethacrylate g 110.0 Benzene (thiophene-free) g.. 413.0 AIBN (VAZO 64) g1.10 t-Dodecyl mercaptan ml 0.70

The resulting graft copolymer is recovered by precipitation of part ofthe copolymer in methanol and the other part in cyclohexane to give acombined yield of 87%. Clear, brittle films are obtained from thecyclohexane-or methanolprecipitated products. The methacrylateterminated polystyrene alone has a peak at 32 counts on the chromatogramof the GPC. However, a GPC chromatogram on the unworked-up product ofthe graft copolymer illustrates that no unreacted methacrylatemacromolecular monomer is detectable at 32 counts. Therefore, it must beassumed that all of the methacrylate terminated polystyrenecopolymerized with the methyl methacrylate.

EXAMPLE 32 Preparation Of Graft Copolymer Having Polystyrene SidechainsAnd Poly(butyl acrylate) Backbone By Suspension Copolymerization Byemploying the same methacrylate terminated polystyrene used in Example30 (i.e., M.W.=11,000 and T'w/fi'n less than about 1.1, prepared by theprocedure of Example 8), the following ingredients are charged into aclean, capped, nitrogen purged quart bottle:

G. Distilled water 150.0 Lemol 4288 (5% solution of polyvinyl alcohol)3.0 Disodium phosphate 0.80 Monosodium phosphate 0.05

Thereafter, the following solution is introduced into the bottle viasyringe:

G. Methacrylate terminated polystyrene 20.0 Butyl acrylate 30.0 Lauroylperoxide 0.1

The bottle is rotated for 16 hours, at 65 C., followed by heating for2-3 hours at 86 C. The product beads are washed with water, filtered anddried. The molded film is clear, rubbery, and strong. The transparencyof the film indicates that little unreacted methacrylate terminatedpolystyrene is present.

Unlike copolymerization in DMSO/benzene solution, the reactivity ofmethacrylate terminated polystyrene with acrylic monomers in suspensionpolymerization is that predicted from literature reactivity ratios. Itis seen in Table 3 below that the polymerizable macromolecular monomerhas a greater relative reactivity than the butyl acrylate monomer. Therelative reactivity ratio, r of the methacrylate terminated polystyrene(M with butyl acrylate (M is about 0.4 (Table 3). This corresponds withthe literature value of 0.37 for methyl methacrylate/ butyl acrylate.

TABLE 3 Composition of methacrylate terminated polystyrene-butylacrylato copolymers prepared by suspension polymerization T2= percentCopoly- BA con- Percent Macromer comversion/ macro- Butyl molecularposition percent molecular Polymeracrylat-e monomer (percentmacromonomer ization eonverconvermacromolecular in montime, sion, sion,molecular monomer omer teed minutes percent percent monomer) conversionEXAMPLE 33 Preparation Of Graft Copolymer Having Polystyrene SidechainsAnd Ethyl Acrylate/Butyl Acrylate Backbone By SuspensionCopolymerization A suspension copolymerization using a methacrylateterminated polystyrene prepared by the procedure of EX- ample 8 having amolecular weight of about 16,000 and a Hw/lfin of less than about 1.1 isconducted by the procedure described below. An aqueous solution and amonomer solution were both freshly prepared before use. The ingredientsof the aqueous stabilizer solution and monomer solution are as follows:

Aqueous Stabilizer Solution: G. Distilled water 300.0 5% Lemol 42-88polyvinyl alcohol solution (Borden) 3.0 Disodium phosphate -2 1.6Monomer Solution:

Methacrylate terminated polystyrene 30.0 Ethyl acrylate (Rohm & Haas)35.0 Butyl acrylate (Rohm & Haas) 35.0 Benzene (thiophene-free) 14.0Lauroyl peroxide 0.084

The 5% polyvinyl alcohol solution is prepared by dissolving Lemol 42-88in distilled water. The aqueous stabilizer solution is charged to arinsed quart bottle, and the bottle is capped with a butyl rubbergasketed cap having a Mylar film lining. The bottle is purged withnitrogen via syringe'needle before introducing the monomer solution.

The monomer solution is then charged to the bottle with a hypodermicsyringe, and the 'bottle is placed in a bottle polymerization bath androtated at 30 r.p.m. at 55 C. for 16 hours. The polymerization reactionis completed using the following temperature cycle. The bath temperatureis raised to 65 C. for 3 hours, 80 C. for one hour and 4 hours at 9295C. The suspension is then cooled, filtered, washed with water and driedat ambient temperature.

The beads are milled for 2 minutes at 145 C. roll temperature foranalysis and physical testing. The yield is 91.6% of theoretical (thereis some loss of material dur- 40 ing milling). The amount of unreactedmethacrylate terminated polystyrene in the product is 3.3

The samples are prepared for physical testing by briefly milling thedried polymer beads prior to molding specimens in order to eliminateinsoluble gel. The milled products are dissolved in THF for GPCdetermination for unreacted methacrylate terminated polystyrene. Themolded specimens which had not undergone shearing by milling did notgenerally develop optimum physical properties. All products for analysisare milled 2 minutes on a lab mill with a tight nip and 145 C. rolltemperature. Specimens for tensile testing are compression molded for 10minutes at 170 C. and 1100 p.s.i. Only contact pressure is applied untilthe platens reach the required temperature, then full pressure isapplied to the mold. Pressure is maintained while cooling the mold toprevent the formation of bubbles.

The molded sheets (19 mils) of the incorporated methacrylate terminatedpolystyrene copolymer of this example are tough and transparent and theproperties are described in Table 4 below.

TABLE 4 Properties of 30% Methacrylate Terminated Polystyrene Copolymerwith 1:1 EA:BA

Tensile strength, p.s.i. 1630 Ultimate elongation, percent a 475 Tensileset (percent increase of original length) a Tensile testing wasconducted on Instron at 10 inches/ minute crosshead rate.

EXAMPLE 34 Preparation of Graft Copolymer Having Polystyrene SidechainsAnd Poly( butyl acrylate) Backbone by Suspension Copolymerization A2-liter glass resin kettle (5 inch diameter) immersed in a temperaturecontrolled water bath is charged with 600 grams of an aqueous stabilizersolution containing 600 grams of distilled Water, 3.0 grams of 5% Lemol42- 88 polyvinyl alcohol solution (Borden), and 3.20 grams of disodiumphosphate. The reactor is equipped with a condenser, thermometer,nitrogen inlet, and a stirrer with a 4% inch crescent shaped l-pieceTeflon paddle. While heating up the aqueous solution, the reactor ispurged with nitrogen at 100200 ml./min. for minutes. The nitrogen flowis reduced, and 225.2 grams of a monomer solution is charged to thereactor. The monomer solution consists of 60.0 grams of a methacrylateterminated polystyrene prepared by the procedure of Example 8 and havinga molecular weight of about 11,000, 140.0 grams of butyl acrylate, 28.0grams of benzene (thiophene-free), and 0.280 gram of lauroyl peroxide(Alperox, Lucidol). The stirrer is adjusted so the blade is 1.5 inchesbelow the surface, and stirring is started at 300 r.p.m., then reducedto 230 r.p.m. (Monomer pooling is observed at slower stirring speeds).The bath temperature is maintained at 62 C. with an internal temperatureof 6l C. After 1% hours, monomer droplets are observed as beingconverted into beads. The internal temperature is raised to C. after 5/2 hours, and the polymerization is finished in another 1 /2 hours. Theproduct is filtered through a 60-mesh screen, washed with distilledwater and allowed to dry at room temperature. The weight of the driedpolymer beads (5-12 mm. length, 3-4 mm. diameter) is 190.7 grams. Aftermilling (2 minutes at C.) then molding of the product for 10 minutes atC., a transparent elastorner is obtained.

1. A COPOLYMERIZABLE MARCROMOLECULAR MONOMER HAVING A SUBSTANTIALLYUNIFROM MOLECULAR DISTRIBUION SUCH THAT ITA S RATIO $W/$N IS NOTSUBSTANTIALLY ABOVE ABOUT 1.1, WHEREIN $W IS THE WEIGHT AVERAGEMOLECULAR WIEHGT OF THE MACROMOLECULAR MONOMER, AND $N IS THE NUMBERAVERAGE MOLECULAR WEIGHT OF THE MACROMOLECULAR MONOMER, SAIDMACROMOLECULAR MONOMER BEING REPRESENTED BY THE STRUCTURAL FORMULA: